Amplifier board size: 29x36CMBluetooth 50, QCC3034, support for , AAC, , APTXLL, APTXHD, on, with call function, the default volume is maximum5V: drive dual 4 Euro 3W65V: drive dual 4 ohm 5WVCC, GND: supply pinsLN(-), LP(+): Left speakerRN(-), RP(+): Right speakerCOM: The common terminal of the key, the other end of the key is connected to VOL+, VOL-, PREV, , PLY respectivelyM+, M-: microphone head (with positive and negative electrodes)Key Description:VOL+: short press to increase the volume, long press to continuously increase the volumeVOL-: Short press to decrease the volume, long press to continuously decrease the volume: short press the songPREV: short press the previous songPLY: short press to play/pause/answer/ up, long press for 1 second to reject incoming callsSpecial function description:PLY: long press for 3 seconds to force into pairing mode, long press for 6 seconds to clear the pairing listPLY+VOL+: Press and hold for 1 second at the same time to enter the search TWS modePLY+VOL-: Press and hold for 1 second at the same time to enter the searched TWS modeVOL++VOL-: Press and hold for 1 second at the same time to disconnect TWSColour:greenMaterial:PCBPackage Contents:1 x AmplifierOnly 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.