Features: DC isolated 5V/12V power supply: suitable for speaker, amplifier, car to increase the Bluetooth-compatible function, the perfect solution to the total current sound, noise; No DC isolated power supply: suitable for lithium-battery-powered, making Bluetooth-compatible headset; GND-,BAT are powered by a 3.7V lithium-battery; KCOM: The common end of the button, with the other end of the button connected to VOL+, VOL-, PREV, NEXT-PLAY respectively M+M-: MiTou (with positive and negative electrodes); CSR8645 Low-power Consumption Bluetooth-compatible5.0 module; Specifications: Material:Electronic Component GND-, VCC: 5V or 12v power supply, according to DC isolation selection; OUTL, AGND, OUTR: single ended output, connected to headphones, amplifiers, audio, etc; Option Type:No DC isolated power supply Module,5V power supply Module,12V power supply Module; Package Includes: 1xBluetooth-compatible5.0 Module note: Please allow 1-2cm errors due to manual measurement,please make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.