Feature:1. AUX+Bluetooth audio input, subwoofer+left and right channel output.Use large-capacity energy storage capacitors2. Low noise level operational amplifier, external antenna or antenna base solder joint3. Adapter power supply above DC12‑24V/5A (24V battery pack is not allowed)4. 2.1 channel. Anti‑reverse connection, overheating, overcurrent, short circuit protection5. Output power, left and right channels <50W, subwoofer <100w.Adaptation speaker 20-100W, 4-8ΩSpecification:Item Type: Digital Power Amplifier ModuleBT Version: 5.0 (Unobstructed, Approx. 15 Meters / 16in)Input Sensitivity: 500mVInput Method: AUX+BTNumber of Channels: 2.1 ChannelsPower Amplifier Chip: Domestic Power Amplifier ChipAdapter Power Supply: Above DC12-24V/5A (24V Battery Pack is Not Allowed)Adapted Speakers: 20-100W 4-8ΩOutput Power: Left and Right Channels <50WSubwoofer <100WProtection Mechanism: Anti-Reverse Connection, Overheating, Overcurrent, Short Circuit Protection.Package List:1 x Digital Power Amplifier Module2 x Board1 x Screwdriver1 x Screw Accessories5 x Snap1 x ConnectorNote:1.Please allow 0‑2 cm error due to manual measurement. Thanks for your understanding.2.Only when the audio input is enough and the power supply voltage/current is enough, there will be enough output power.3.The higher the power supply voltage, the greater the output power, and the smaller the speaker impedance, the greater the output power.4.Please make sure that the power of the adapter power supply is greater than the actual working power of the amplifier.