Support TWS pair box (2 wireless stereo speakers), no call function, Qualcomm CSRA64110 low consumption, on, default volume is maximum, self-boost 65V, lithium battery supply to drive 4 ohm 5/6/8W speakers, Mono (left and right channels combined)VCC, GND: 33-42V (powered by lithium battery)SPK: Speaker (4 Euro 5/6/8W)COM: The common terminal of the key, the other end of the key is connected to VOL+, VOL-, PREV, , PLY respectivelyAmplifier board size: 435x36CMKey "VOL+": short press to increase the volume, long press to continuously increase the volume"VOL-": Short press to decrease the volume, long press to continuously decrease the volume"": short press the song"PREV": short press the previous song"PLY": short press to play/pauseSpecial function "PLY": long press for 3 seconds to force into pairing mode, long press for 6 seconds to clear the pairing list"PLY"+"VOL+": Press and hold for 1 second at the same time to enter the search TWS mode"PLY"+"VOL-": Press and hold for 1 second at the same time to enter the searched TWS mode"VOL+"+"VOL-": Press and hold for 1 second at the same time to disconnect TWSMaterial: PCBcolour: GreenPackage 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.