1. Supports pairing (two speakers form a wireless stereo speaker), with call functionality (selectable within the category). for QCC5125 low-power chip supports , AAC, , APTXLL, APTXHD, and LDAC. Powers on at maximum volume by default. Supports for Android app-enabled Bluetooth name modification (Chinese language supported), pairing password, custom EQ, and power-on/off beep. 2. When using pairing, use the highest protocol. 3. When clearing pairing information, use the highest LDAC protocol (default for 5125). 4. VCC, GND: 3.3-4.2V. 5. R/L: Speakers (2 x 4-ohm 5/6/8W). M+, M-: Microphones (with positive and negative terminals) KCOM: Common terminal for buttons. Connect the other ends of the buttons to VOL+, VOL-, PREV, NEXT, and PLAY, respectively. Button Description: "VOL+": Short to increase volume, long to increase volume "VOL-": Short to decrease volume, long to decrease volume "NEXT": Short to go to track, long to increase volume "PREV": Short to go to the previous track, long to decrease volume "PLAY": Short to play/pause/answer/end call, long for 1 second to reject call Special Function Description: "PLAY": and hold for 3 seconds to force pairing mode. and hold for 6 seconds to clear the pairing list. "PLAY" + "VOL+": and hold simultaneously for 1 second to enter host mode and search for . "PLAY" + "VOL-": and hold simultaneously for 1 second to enter slave mode and search for . "VOL+" + "VOL-": and hold simultaneously for 1 second to disconnect . "NEXT" + "PREV": and hold simultaneously for 6 seconds and then release to clear pairing information and password, and reset. Color: Green Material: PCB Packa Contents: 1 x QCC5125 LDAC Stereo Audio Module Only 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.