Name: 50W+50W stereo bluetooth digital power amplifier board Model:XY-AP50L Supply voltage: DC5-12V/24V (the higher the voltage, the greater the output power) Transmission distance: 15m Bluetooth version: 5.0 Number of channels: left and right channels Adapted speakers: 30W-200W 4 ohms 8 ohms 16 ohms Colour:Black Material:plastic Size:52x52x16mm Package Contents: 4 x 50W+50W stereo bluetooth digital power amplifier board Precautions for use: 1. Use the power amplifier board as far away as possible from the WIFI signal (router) 2. The recommended power supply voltage is DC 5~12V/24V, if it exceeds 26V, the chip burn. 3. The power supply current is recommended to be above 2A. 4. The speaker cable should not be too long, and that it is suitable within 1 meter 5. Pay attention to static electricity protection. Before touching the power amplifier board, you must first release the static electricity on your hands to avoid static electricity from breaking down the chip. Bluetooth chips are more sensitive to static electricity. 6. It is recommended to adapt the speaker with a rated power of 40W and above to avoid the speaker from heating and burning Only the above package content, other products are not included. Note: Light 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.