Bluetooth version: 5.0 (without sunscreen, 15 meters) Output channel: 2.0 channel Chip : AP3050D Working mode: class D Audio input: support bluetooth 5.0,AUX, U disk Play Rated output : 50W+50W Frequency response: 20Hz to 20KHz Working voltage: DC8V to DC26V Recommended voltage: DC19V Fit speaker parameters: 4-8 ohms NOTE: 1.For DIY---The outer casing is a material package, It needs to be assembled by itself, and the material package is given a screwdriver. 2.---Attention!The heat sink tape glue needs to be pasted to the chip by itself. 3.For ---The switch on the board is standby switch. After the switch is off, the machine is in standby state with low consumption. If the is completely turned off or the DC plug on the machine can be unplugged for a long time. Colour:black Material:PCB+Plastic+Metal Size:56 x 50 x 18mm Package Contents: 1 x amplifier board 1 x terminal 1 set x shell material package Only the above package content, other products are not included. Note: Light reflection and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.