Echomaster MM-4320-BT - Car 4.3" Factory Mount Monitor with Built In BluetoothEchomaster MM 4320 BT Car 4. 3" Factory Mount Monitor with Built In Bluetooth Backing up your car safely just got a whole lot easier. This sleek universal replacement rearview mirror with 4. 3" monitor, replaces your old mirror with a fully integrated LCD monitor, pairing perfectly with any of EchoMasters many blind spot camera and back up camera options. Dual video inputs mean you can use the monitor for both front and rear view cameras, giving you