1、High quality power amplifier board, with two audio input methods, AUX and bluetooth, and adopts 5.0 bluetooth version, which has higher transmission efficiency and longer transmission distance. 2、2.1 channel, the maximum output power is 2×50W+100W. With antenna and antenna base, the signal is better, the efficiency is high, and the anti interference ability is strong. 3、It has short circuit protection, over current, over heating, and anti reverse protection to prevent it from failing completely. And when an overload occurs, the device protects itself from damage. 4、Copper DC connector + shed type terminal, can withstand high current, does not generate heat, and is not easy to damage the wires. No DC head lead, compatible with the input power interface of this product. 5、With bass, treble, subwoofer frequency and volume control, you can easily adjust the volume. It can be widely used in shop solicitation, home theater, speakers, etc. Item Type: Audio Amplifier Board Material: PCB Purpose: Subwoofer Power Amplifier Board Model: ZK-TB21 Chip: TPA3116D2 Bluetooth Version: 5.0 (Unobstructed 10m / 32.8ft) Audio Input: AUX + Bluetooth Number Of Channels: 2.1 Channels Input Sensitivity: 500mV Adapted Power Supply Voltage: 12-24V/5A Or More (Do Not Connect 24V Battery Pack) Speaker: 20-100W, 4-8Ω Output Power: Maximum 50W (Left And Right Channel), Maximum 100W (Subwoofer) Protection Mechanism: Overvoltage, Undervoltage, Overheating, DC Detection, Short Circuit Protection 1 x Amplifier Board Module 2 x Acrylic Board 1 x Screwdriver 9 x Screw 4 x Brass Connecting Rod 4 x Brass Terminal 5 x Knob 1 x Wire Input Socket