1: Power amplifier chip: RT7498E 2: Protection mechanism: anti-reverse connection, undervoltage, overheating, overcurrent, short circuit protection 3: Widely used 4: Long-life ultra-quiet fan (blocked rotor does not burn, no noise) 5: Simple to use and easy to understand Product name: 2.1 Channel Bluetooth Audio Power Amplifier Module Product model: ZK-HT21 Bluetooth version: 5.0 (unobstructed, up to 15 meters) Input method: AUX + Bluetooth + USB (dial button to switch modes and songs) Number of channels: 2.1 channels (left channel + right channel + subwoofer) Amplifier chip: TDA7498E Power supply: DC 15-36V (under voltage protection below 9V, 12V power supply supported) Compatible speakers: 30-200W, 4-8 Output power: - Left and right channels: 160W - Subwoofer: 220W Protection features: anti-reverse connection, undervoltage, overheating, overcurrent, short circuit protection Product dimensions: 145 x 126 x 28mm Product weight: 327g (net weight) Note: When the audio signal input is sufficient and the power supply voltage/current is adequate, maximum output power can be achieved. Higher power supply voltage results in greater output power. Lower speaker impedance also increases output power. Ensure the adapter power rating exceeds the amplifier's actual operating power requirement. Color: Black Material: Composite Materials Package Contents: 1 x Power amplifier board kit (Other items not included) Note: Lighting and display differences may cause slight color variation between the image and the actual item. Measurement tolerance: +/- 1-3cm.