Features: The power amplifier board uses TDA 7377 integrated chip, high power, stereo dual-channel output 40w+40W. High power, good sound quality, compatible with 3-6In bookshelf speakers, floor-standing speakers. Amplifier with midrange adjustment, treble adjustment, bass adjustment potentiometer, and indicator light. The wiring is very simple, you can use it by referring to the wiring diagram, and it is the first choice for beginners. It is a portable power amplifier board for home computers, motorcycles, cars, etc. Package Includes: 1 Set Stereo Audio Amplifier Specifications: Channels: 2 (2.0) Model: DX-7377 Output Power: 40W+40W Power Input: AC/DC 9-15v/20-40W Frequency Response: 20hz-20khz Size: 10x11x3.5cm Weight: 100g/0.22lb Maximum Power Per Channel: 40W note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment.