diff --git a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt
index 818c0fb..9db6dbb 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayDefinition.kt
@@ -1,27 +1,34 @@
 package nl.astraeus.tba
 
-enum class DataType(val size: Int) {
+enum class DataType(
+  val size: Int,
+  val bytesUsedInternally: Int = 0
+) {
   BYTE(1),
   SHORT(2),
   INT(4),
   LONG(8),
   FLOAT(4),
   DOUBLE(8),
-  STRING(-1), // max length 65535
-  CLOB(-1), // max length 2^32-1
-  BLOB(-1), // max length 2^32-1
+  STRING(-1, 2), // max length 65535
+  CLOB(-1, 4), // max length 2^32-1
+  BLOB(-1, 4), // max length 2^32-1
   ;
 }
 
 class Type(
   val name: String,
   val type: DataType,
-  val size: Int = if (type.size == -1) {
+  size: Int = 0,
+) {
+  val size: Int = if (size > 0) {
+    size + type.bytesUsedInternally
+  } else if (type.size == -1) {
     throw IllegalArgumentException("Size must be defined for type ${type.name}")
   } else {
-    type.size
-  },
-)
+    type.size + type.bytesUsedInternally
+  }
+}
 
 open class ByteArrayDefinition(
   vararg types: Type,
@@ -31,4 +38,4 @@ open class ByteArrayDefinition(
   val size: Int by lazy {
     this.types.sumOf { it.size }
   }
-}
\ No newline at end of file
+}
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayExtentions.kt b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayExtentions.kt
deleted file mode 100644
index 6a6bc3d..0000000
--- a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayExtentions.kt
+++ /dev/null
@@ -1,69 +0,0 @@
-package nl.astraeus.tba
-
-fun ByteArray.setShort(index: Int, value: Short) {
-  this[index] = (value.toInt() shr 8).toByte()
-  this[index + 1] = value.toByte()
-}
-
-fun ByteArray.getShort(index: Int): Short {
-  return ((this[index].toInt() shl 8) or (this[index + 1].toInt() and 0xff)).toShort()
-}
-
-fun ByteArray.setInt(index: Int, value: Int) {
-  this[index] = ((value shr 24) and 0xff).toByte()
-  this[index + 1] = ((value shr 16) and 0xff).toByte()
-  this[index + 2] = ((value shr 8) and 0xff).toByte()
-  this[index + 3] = (value and 0xff).toByte()
-}
-
-fun ByteArray.getInt(index: Int): Int {
-  return (
-      (this[index].toInt() shl 24) or
-      ((this[index+1].toInt() shl 16) and 0xff0000) or
-      ((this[index+2].toInt() shl 8) and 0xff00) or
-      (this[index+3].toInt() and 0xff)
-    )
-}
-
-fun ByteArray.setLong(index: Int, value: Long) {
-  this[index] = ((value shr 56) and 0xff).toByte()
-  this[index + 1] = ((value shr 48) and 0xff).toByte()
-  this[index + 2] = ((value shr 40) and 0xff).toByte()
-  this[index + 3] = ((value shr 32) and 0xff).toByte()
-  this[index + 4] = ((value shr 24) and 0xff).toByte()
-  this[index + 5] = ((value shr 16) and 0xff).toByte()
-  this[index + 6] = ((value shr 8) and 0xff).toByte()
-  this[index + 7] = (value and 0xff).toByte()
-}
-
-fun ByteArray.getLong(index: Int): Long {
-  return (
-    (this[index].toLong() shl 56) or
-      ((this[index+1].toLong() and 0xff) shl 48) or
-      ((this[index+2].toLong() and 0xff) shl 40) or
-      ((this[index+3].toLong() and 0xff) shl 32) or
-      ((this[index+4].toLong() and 0xff) shl 24) or
-      ((this[index+5].toLong() and 0xff) shl 16) or
-      ((this[index+6].toLong() and 0xff) shl 8) or
-      (this[index+7].toLong() and 0xff)
-    )
-}
-
-fun ByteArray.setDouble(index: Int, value: Double) = this.setLong(index, value.toRawBits())
-fun ByteArray.getDouble(index: Int): Double = Double.fromBits(this.getLong(index))
-
-fun ByteArray.setFloat(index: Int, value: Float) = this.setInt(index, value.toRawBits())
-fun ByteArray.getFloat(index: Int): Float = Float.fromBits(this.getInt(index))
-
-fun ByteArray.getString(index: Int): Pair<String, Int> {
-  val length = this.getInt(index)
-  val str = this.copyOfRange(index + 4, index + 4 + length).decodeToString()
-  return Pair(str, index + 4 + length)
-}
-
-fun ByteArray.setString(index: Int, value: String): Int {
-  val bytes = value.encodeToByteArray()
-  this.setInt(index, bytes.size)
-  bytes.copyInto(this, index + 4)
-  return index + bytes.size + 4
-}
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt
index bbf1d87..a9f047d 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayHandler.kt
@@ -2,9 +2,13 @@ package nl.astraeus.tba
 
 class MutableByteArrayHandler(
   initialSize: Int = 1024,
-  buffer: ByteArray = ByteArray(initialSize)
+  buffer: SlicedByteArray = SlicedByteArray.wrap(ByteArray(initialSize), 0, initialSize),
 ) : ByteArrayHandler(initialSize, buffer) {
 
+  constructor(buffer: ByteArray, range: IntRange = buffer.indices) : this(
+    buffer = SlicedByteArray.wrap(buffer, range.first, range.last - range.first)
+  )
+
   operator fun set(index: Int, value: Byte) {
     buffer[index] = value
   }
@@ -32,8 +36,8 @@ class MutableByteArrayHandler(
     buffer[index + 7] = (value and 0xff).toByte()
   }
 
-  fun setFloat(index: Int, value: Float) = buffer.setInt(index, value.toRawBits())
-  fun setDouble(index: Int, value: Double) = buffer.setLong(index, value.toRawBits())
+  fun setFloat(index: Int, value: Float) = setInt(index, value.toRawBits())
+  fun setDouble(index: Int, value: Double) = setLong(index, value.toRawBits())
 
   fun setString(index: Int, value: String, maxLength: Int): Int {
     val bytes = value.encodeToByteArray()
@@ -41,7 +45,7 @@ class MutableByteArrayHandler(
       throw IllegalArgumentException("String is too long")
     }
     this.setShort(index, bytes.size.toShort())
-    bytes.copyInto(buffer, index + 2)
+    bytes.copyInto(buffer.data, index + 2)
     return index + bytes.size + 2
   }
 
@@ -51,7 +55,7 @@ class MutableByteArrayHandler(
       throw IllegalArgumentException("String is too long")
     }
     this.setInt(index, bytes.size)
-    bytes.copyInto(buffer, index + 4)
+    bytes.copyInto(buffer.data, index + 4)
     return index + bytes.size + 4
   }
 
@@ -60,7 +64,7 @@ class MutableByteArrayHandler(
       throw IllegalArgumentException("String is too long")
     }
     this.setInt(index, bytes.size)
-    bytes.copyInto(buffer, index + 4)
+    bytes.copyInto(buffer.data, index + 4)
     return index + bytes.size + 4
   }
 
@@ -68,15 +72,11 @@ class MutableByteArrayHandler(
 
 open class ByteArrayHandler(
   size: Int = 1024,
-  var buffer: ByteArray = ByteArray(size),
-  val firstIndex: Int = 0,
-  val lastIndex: Int = buffer.size
+  var buffer: SlicedByteArray = SlicedByteArray.wrap(ByteArray(size), 0, size),
 ) {
 
-  constructor(buffer: ByteArray, range: IntRange) : this(
-    buffer = buffer,
-    firstIndex = range.first,
-    lastIndex = range.last
+  constructor(buffer: ByteArray, range: IntRange = buffer.indices) : this(
+    buffer = SlicedByteArray.wrap(buffer, range.first, range.last - range.first)
   )
 
   operator fun get(index: Int): Byte {
@@ -109,35 +109,34 @@ open class ByteArrayHandler(
       )
   }
 
-  fun getFloat(index: Int): Float = Float.fromBits(buffer.getInt(index))
-  fun getDouble(index: Int): Double = Double.fromBits(buffer.getLong(index))
+  fun getFloat(index: Int): Float = Float.fromBits(getInt(index))
+  fun getDouble(index: Int): Double = Double.fromBits(getLong(index))
 
   fun getString(index: Int): String {
     val length = getShort(index)
-    val str = buffer.copyOfRange(index + 2, index + 2 + length).decodeToString()
+    val str = buffer.data.copyOfRange(index + 2, index + 2 + length).decodeToString()
     return str
   }
 
   fun getClob(index: Int): String {
     val length = getInt(index)
-    val str = buffer.copyOfRange(index + 4, index + 4 + length).decodeToString()
+    val str = buffer.data.copyOfRange(index + 4, index + 4 + length).decodeToString()
     return str
   }
 
   fun getBlob(index: Int): ByteArray {
     val length = getInt(index)
-    val str = buffer.copyOfRange(index + 4, index + 4 + length)
+    val str = buffer.data.copyOfRange(index + 4, index + 4 + length)
     return str
   }
 
   fun slice(range: IntRange): ByteArrayHandler {
     return ByteArrayHandler(
-      buffer,
-      range
+      buffer = SlicedByteArray(this.buffer.data, range.first, range.last - range.first)
     )
   }
 
   fun asMutable(): MutableByteArrayHandler {
-    return MutableByteArrayHandler(buffer = buffer.copyOfRange(firstIndex, lastIndex))
+    return MutableByteArrayHandler(buffer = SlicedByteArray(buffer.data, 0, buffer.data.size))
   }
 }
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt
index 9215dc6..0f26c76 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/ByteArrayProperties.kt
@@ -23,7 +23,10 @@ abstract class ByteArrayPropertyWithLength<T>(
 
   protected fun getMaxLength(thisRef: TypedByteArray): Int {
     if (maxLength == null) {
-      maxLength = thisRef.typeMap[name]!!.size - 2
+      val type = thisRef.typeMap[name] ?: throw IllegalArgumentException(
+        "Type $name not found in typemap in $thisRef"
+      )
+      maxLength = type.size
     }
     return maxLength!!
   }
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/SlicedByteArray.kt b/src/commonMain/kotlin/nl/astraeus/tba/SlicedByteArray.kt
new file mode 100644
index 0000000..8896962
--- /dev/null
+++ b/src/commonMain/kotlin/nl/astraeus/tba/SlicedByteArray.kt
@@ -0,0 +1,32 @@
+package nl.astraeus.tba
+
+class SlicedByteArray(
+  val data: ByteArray,
+  val offset: Int,
+  val length: Int
+) {
+  val size: Int
+    get() = length
+
+  operator fun get(index: Int): Byte {
+    return data[offset + index]
+  }
+
+  operator fun set(index: Int, value: Byte) {
+    data[offset + index] = value
+  }
+
+  fun copyInto(dest: ByteArray, destOffset: Int, length: Int) {
+    data.copyInto(dest, destOffset, offset, offset + length)
+  }
+
+  companion object {
+    fun wrap(
+      data: ByteArray,
+      offset: Int,
+      length: Int
+    ): SlicedByteArray {
+      return SlicedByteArray(data, offset,length)
+    }
+  }
+}
diff --git a/src/commonMain/kotlin/nl/astraeus/tba/TypedByteArray.kt b/src/commonMain/kotlin/nl/astraeus/tba/TypedByteArray.kt
index 291c50c..ff50c92 100644
--- a/src/commonMain/kotlin/nl/astraeus/tba/TypedByteArray.kt
+++ b/src/commonMain/kotlin/nl/astraeus/tba/TypedByteArray.kt
@@ -19,6 +19,8 @@ open class TypedByteArray(
     }
   }
 
+  constructor(vararg types: Type): this(ByteArrayDefinition(*types))
+
   constructor(data: ByteArray): this(ByteArrayDefinition()) {
     this.data = MutableByteArrayHandler(buffer = data)
   }
diff --git a/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt b/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt
index ac9d305..80354c6 100644
--- a/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt
+++ b/src/commonTest/kotlin/nl/astraeus/tba/ExtendedByteArrayDefinition.kt
@@ -9,12 +9,10 @@ class ExtendedByteArrayDefinition {
   open class MessageByteArray(
     vararg types: Type
   ) : TypedByteArray(
-    ByteArrayDefinition(
       Type("messageType", DataType.BYTE),
       Type("messageLength", DataType.SHORT),
       Type("message", DataType.STRING, 1024),
       *types,
-    )
   ) {
     var messageType by byte("messageType")
     var messageLength by short("messageLength")
diff --git a/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArraySize.kt b/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArraySize.kt
new file mode 100644
index 0000000..2a7f541
--- /dev/null
+++ b/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArraySize.kt
@@ -0,0 +1,36 @@
+package nl.astraeus.tba
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class TypedByteArraySize {
+
+  class Person() : TypedByteArray(
+      Type("name", DataType.STRING, 100),
+  ) {
+    var name by string("name")
+
+    constructor(name: String): this() {
+      this.name = name
+    }
+
+    constructor(data: ByteArray): this() {
+      this.data = MutableByteArrayHandler(buffer = data)
+    }
+  }
+
+  @Test
+  fun testPersonSize() {
+    val type = Type("name", DataType.STRING, 10)
+
+    assertEquals(12, type.size)
+
+    val person = Person("Test")
+
+    assertEquals(102, person.data.buffer.size)
+
+    val clobType = Type("long-name", DataType.CLOB, 100)
+
+    assertEquals(104, clobType.size)
+  }
+}
diff --git a/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArrayTest.kt b/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArrayTest.kt
index 8cd2c2b..40f746d 100644
--- a/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArrayTest.kt
+++ b/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArrayTest.kt
@@ -6,11 +6,9 @@ import kotlin.test.assertEquals
 class TypedByteArrayTest {
 
   class Person() : TypedByteArray(
-    ByteArrayDefinition(
-      Type("name", DataType.STRING, 102),
+      Type("name", DataType.STRING, 100),
       Type("age", DataType.BYTE),
       Type("length", DataType.SHORT),
-    )
   ) {
     var name by string("name")
     var age by byte("age")
@@ -33,6 +31,7 @@ class TypedByteArrayTest {
 
     assertEquals(4, person.data.buffer[1])
     assertEquals(42, person.data.buffer[102])
+    assertEquals(180.toByte(), person.data.buffer[104])
 
     assertEquals("Test", person.name)
     assertEquals(42.toByte(), person.age)
@@ -42,7 +41,7 @@ class TypedByteArrayTest {
   @Test
   fun testToByteArrayAndBack() {
     val person = Person("Test", 42, 180)
-    val bytes: ByteArray = person.data.buffer
+    val bytes: ByteArray = person.data.buffer.data
 
     val person2 = Person(bytes)
 
diff --git a/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArrayWithByteArrayTest.kt b/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArrayWithByteArrayTest.kt
new file mode 100644
index 0000000..429f0aa
--- /dev/null
+++ b/src/commonTest/kotlin/nl/astraeus/tba/TypedByteArrayWithByteArrayTest.kt
@@ -0,0 +1,54 @@
+package nl.astraeus.tba
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class TypedByteArrayWithByteArrayTest {
+
+  class Person1() : TypedByteArray(
+      Type("name", DataType.STRING, 10),
+  ) {
+    var name by string("name")
+
+    constructor(name: String): this() {
+      this.name = name
+    }
+
+    constructor(data: ByteArray): this() {
+      this.data = MutableByteArrayHandler(buffer = data)
+    }
+  }
+
+  class Company() : TypedByteArray(
+      Type("name", DataType.STRING, 10),
+      Type("person", DataType.BLOB, 12)
+  ) {
+    var name by string("name")
+    var personData by blob("person")
+    val person by lazy { Person1(personData) }
+
+    constructor(name: String, person: Person1): this() {
+      this.name = name
+      this.personData = person.data.buffer.data
+    }
+
+    constructor(data: ByteArray): this() {
+      this.data = MutableByteArrayHandler(buffer = data)
+    }
+  }
+
+  @Test
+  fun testPersonSize() {
+    val person = Person1("A Name")
+
+    assertEquals(12, person.data.buffer.size)
+
+    val company = Company("A Company", person)
+
+    assertEquals("A Name", company.person.name)
+
+    company.person.name = "2nd Name"
+
+    assertEquals("2nd Name", company.person.name)
+  }
+}