Features 1、AUX+Bluetooth audio input, subwoofer+left and right channel output.Use large-capacity energy storage capacitors 2、Low noise level operational amplifier, external antenna or antenna base solder joint 3、Adapter power supply above DC12‑24V/5A (24V battery pack is not allowed) 4、2.1 channel. Anti‑reverse connection, overheating, overcurrent, short circuit protection 5、Output power, left and right channels &lt;50W, subwoofer &lt;100w.Adaptation speaker 20-100W, 4-8Ω Specification Item Type: Digital Power Amplifier Module BT Version: 5.0 (Unobstructed, Approx. 15 Meters / 16in) Input Sensitivity: 500mV Input Method: AUX+BT Number of Channels: 2.1 Channels Power Amplifier Chip: Domestic Power Amplifier Chip Adapter Power Supply: Above DC12-24V/5A (24V Battery Pack is Not Allowed) Adapted Speakers: 20-100W 4-8Ω Output Power: Left and Right Channels <50W Subwoofer <100W Protection Mechanism: Anti-Reverse Connection, Overheating, Overcurrent, Short Circuit Protection Package List 1 x Digital Power Amplifier Module 2 x Board 1 x Screwdriver 1 x Screw Accessories 5 x Snap 1 x Connector