---
title: getMTU()
framework: IOBluetooth
role: symbol
role_heading: Instance Method
path: iobluetooth/iobluetoothrfcommchannel/getmtu()
---

# getMTU()

Returns the channel maximum transfer unit.

## Declaration

```swift
func getMTU() -> BluetoothRFCOMMMTU
```

## Return Value

Return Value Channel MTU size .

## Discussion

Discussion Returns the length of the largest chunk of data that this channel can carry. If the caller wishes to use the write:length:sleep: api the length of the data can not be bigger than the channel MTU (maximum transfer unit).