Specification:Chip: TDA7492PPower: 2.1 interface 8-25V DC power supplyAudio input: CSR8635 Bluetooth chip, Bluetooth V4.0(stereo input various versions of the bluetooth connection)Output Impedance: 8Ω(Best), 4/6/8/16Ω impedance can drive speakersOutput Power: Add pre-5532 output foot (powered 25V, 6Ω impedance output 25W+25W, 8ohm impedance output 2x40W dual-channel) Feature:The sound quality is very good, big power.DIP switches can be adjusted directly after the amp gain more respect and better promote greater damping horn.