Shop name:Chong Qing Shuo Yue Ke Ji You Xian Gong Si No output filter required; single-ended input " on, " noise suppression No impact sound when switching Overcurrent protection, overheating protection, undervoltage protection The standard supply is 12V, the current is 3A, and the maximum voltage is 18V ( supply below 12V is not supported). It is recommended to a 12V3A switching supply for testing. Voltage and settings: Working voltage range: 12V-18V Output : 15W (CLASS D, 12V/4 ohm, =10%) 20W (CLASS D, 15V/4 ohm, =10%) Up to 92% efficiency (18V/8 ohm) colour: green + black Material: plastic Package Contents: 1 x Amplifier Board 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.