1、This board is designed with protective shell, overvoltage protection, undervoltage protection, overheat protection, short circuit protection 2、Using high‑quality production technology, the board is not easy to appear false welding, you can use the board with confidence 3、The amplifier board has simple design, compact body, not taking up too much space, giving you a good experience 4、A variety of input modes, such as BT input, audio input, U disk or computer USB input, can meet the needs of various working situations 5、Equipped with button cover, knob cover, heat sink, screws and other accessories, so you can use the board more easily Item Type : Amplifier Board Material: Printed Circuit Board Model: ZK-502H Power: 2 x 50W Chip Scheme: TPA311602 (with AM Interference Suppression Function) Audio Input: BT+AUX+U Disk+Computer USB Sound Card Adapter Power Supply: DC 9-24V (high voltage is recommended for high power) Adapted Speakers: 10-100W; 4Ω-8Ω Number of Channels: Left and Right Dual Channels (stereo) BT Version: 5.0 (>15 meters/16yd, unobstructed) Purpose: Amplify Audio Signal to Drive Speakers Applicable Scenarios: Sound Engineering, Electronic Equipment, Industrial Engineering Voltage: 12V----8 Ohms/12W(left channel) +12W (right channel), 4 Ohms/20W+20W 15V---8 Ohms/18+18W, 4 Ohms/30+30W 19V----8 Ohms/32+32W, 4 Ohms/40+40W 24V---Ohms/38+38W, 4 Ohms/50+50W 1 x Amplifier Board 1 x Button Cover 1 x Knob Cover 1 x Heat Sink 9 x Screw 4 x Copper Pillar 1 x Upper Cover 1 x Lower Cover 1 x DC Power Connector 1 x Screwdriver