Amplifier board size: 6.2x4.4CMBluetooth amplifier board ( 4O3W), support serial port AT to change bluetooth name, support serial port AT control, Bluetooth (with call), transmit audio input, key switch, neutral tone, etc. It can be used as a Demo test board for BK3266 transmitter module. Facilitate customer development and testingNeutral tone = beep tone or electronic tone on, the default transmission function, you can switch between transmission and reception by pressing the buttonColor: greenMaterial: PCBLaunch Instructions:1. that the slave is in the pairing state (requires the slave to have no pairing password)2. After the transmitter module is powered on, press and hold the "PLY button" for 6 seconds until the indicator light flashes to start searching for the slave3. After the pairing is successful, the indicator light of the transmitter module is always on4. After each -on, the connection is normal, first on the transmitter, and then on the slave (requires the slave to have the -on return function)Package Contents:1 x Amplifier BoardOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.