【PROTECTION FUNCTION】XY-S350H Bluetooth power amplifier board has multiple protection mechanisms to ensure its safe operation. With short circuit protection, undervoltage protection, overvoltage protection, clipping protection. 【IMPORTANT REMINDER】the working voltage of the power amplifier board must be above 18V. DC voltage lower than 18V will fail to start the power amplifier board. 1.Bluetooth version: 5.0 (without sunscreen, 15 meters). 2.Output channel: 2.1 channel. 3.Chip model: TPA3251D2*2. 1.Working mode: class D. 2.Static current: 60mA. 3.Work efficiency: 90%. 4.Audio input: support bluetooth, AUX analog signal, U disk / USB sound card. 5.MAX output power : 220W*2+350W. 6.Frequency response: 20Hz to 20KHz. 7.Working voltage: DC18V - 38V. 8.Recommended power voltage: DC24V. 9.Fit speaker parameters: 4-8 ohms. 10.Size: 130 mm * 116 mm * 27mm . 11.Net weight: about 370g