If you need a password to connect to Bluetooth, enter 0123 Bluetooth 5.1 supports 96K 2BIT LDAC and 48K 24BIT -HD; backwards compatible with other Bluetooth formats. The product is designed with one channel of AUX input for easy switching of external wired audio sources. Bluetooth takes priority and automatically switches to AUX state when there is no Bluetooth connection. It is very convenient to switch between AUX and Bluetooth using a silver plated contact high-precision relay, and the signal is non-destructive and sound free. The operational amplifier circuit adopts a ± dual power supply design and is equipped with an operational amplifier base. In the later stage, different operational amplifiers can be replaced to obtain their favorite voices, such as OPA2604, 0PA1612, LM49720, MUSO2, etc. Bluetooth receiving solution: QCC5125 Decoding chip: ES9038Q2M Support mode: Dual lossless -HD LDAC Supports voltage: DC 5-16V note: Depending on the batch, the components on the module may be different from the pictures, but the functions are the same and do not affect use. Material: PCB+electronic components colour: Black Package Contents: 1 x decoding module with power cable and signal cable 1 x antenna 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.