Features: This product has a classical two-stage tone with small distortion and wide adjustment ranges. TrebleBass areregulated independently. The power interfaces is the common power sockets base 5.5x2.1mm. Support bluetooth-compatible connection. Whether you are setting up a home theater or creating a personalized listenings experience, the amplifier board delivers exceptional sound quality and precise tone adjustment. Specifications: Material:Metal Bluetooth-compatible Version: 5.0 （no shielding，15meters） SNR: > 90dB Input: AUX+ bluetooth-compatible Channel: 2（stereo） Power Supply: DC9~24V/3A above (Do not connect to 24V battery pack) Adapter Speaker: 15~100W，4~8Ω Power Supply Voltage: 12V-----8Ω/12W+12W, 4Ω/20W+20W, 15V-----8Ω/18W+18W, 4Ω/30W+30W, 19V-----8Ω/30W+30W, 4Ω/40W+40W , 24V-----8Ω/40W+40W, 4Ω/50W+50W Protections Mechanism: Overheats, Overcurrent, short circuit protections Length:Approx.8.9cm/3.5'' Package Includes: 1x Power Amplifier note: Please allow 1mm errors due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item.