Charging version. Must be powered by a battery. Type-C port is for charging only. Charging version has a switch to power on and off. pairing function. Supports generation 1 antenna. Default volume is maximum. Syncs with phone volume. QCC5125/QCC5124 supports /AAC//APTXLL/APTXHD/LDAC 5124 VM-32/80MHz -2x120MHz 5125 VM-32MHz -120MHZ. The 5124 has a higher clock speed than the 5125, and its dual-core offers higher performance, but the sound quality is the same. Android app allows you to change the Bluetooth name (supports any language), pairing password, custom EQ, power on/off notification tone, and call support (select within the category). When using with a speaker: Use the highest protocol (optimizes connection stability). Clear pairing information: Use the highest protocol LDAC (default for 5125/5124). 3.6-5.5V power supply (select plug-in or rechargeable version within the category). VBAT, GND: Power supply (3.6-5.5V). L, G, R: Audio output. M+, M-: Microphone positive and negative terminals. DCOM, D0, D1: DCOM is the common terminal for the common anode dual-color LED. MUTE: Outputs 3V3 when sound is present, 0V when no sound is present. P5: Outputs 3V3 when Bluetooth is connected, 0V when disconnected. Button Description: "VOL+": Short to increase volume, long to increase volume "VOL-": Short to decrease volume, long to decrease volume "+": Short to go to track, long to increase volume "P/V-": Short to go to the previous track, long to decrease volume "PLAY": Short to play/pause/answer/end call, long to reject call Special Functions: "PLAY": and hold for 3 seconds to force pairing mode, and hold for 6 seconds to clear pairing mode Pairing List "PLAY" + "VOL+": and hold simultaneously for 1 second to enter master mode and search for (beep sound) "PLAY" + "VOL-": and hold simultaneously for 1 second to enter slave mode and search for (beep sound) "VOL+" + "