Product name: 2.1 Channel Bluetooth Audio Amplifier Board Model: S350H Bluetooth version: 5.1 Frequency range: 20Hz-20kHz Signal to noise ratio: 92dB Power supply: DC 18-38V/10A Audio channels: 2.1 channel Audio output: Left and right channels + subwoofer Audio input: Bluetooth, AUX, U disk, USB sound card Output power: 220W x 2 (left and right channels) + 350W (subwoofer) Maximum output power of left and right channels: 220W at 3 ohm, 2-36V DC 175W at 4 ohm, 2-36V DC 100W at 8 ohm, 2-36V DC Maximum output power of subwoofer: 355W at 2 ohm, 2-36V DC 250W at 3 ohm, 2-36V DC 195W at 4 ohm, 2-36V DC Subwoofer compatible speaker: 20W-200W, 2 ohm - 8 ohm Volume adjustment: High-end encoder knob, smooth operation Protection mechanisms: Overvoltage, undervoltage, overheating, clipping, short circuit Special feature: Supports Audio APP control Product dimensions: 133 x 130 x 25mm Color: Black Material: PCB + Metal Package contents: 1 x 2.1 Channel Power Amplifier Board Note: The package includes only the items listed above. Other accessories are not included. Note: Lighting effects and display settings may cause slight color differences between the image and the actual item. Measurement tolerance: +/- 1-3cm.