1. Audio format: Support MP3, WAV, APE etc. 2. Bluetooth function: Support pairing of external Bluetooth devices such as mobile phones for audio playback. 3. External sound input: Support external sound source input to the machine, amplified output. 4. Memory card function: external TF card, support 32GB TF card. 5. USB function: Connect USB (support 32GB) to read music, and easily set up family background music space. Volume adjustment: 15-level electronic volume adjustment function. Power-off memory function: memorize the state played before the last shutdown. Power: AC110V-250V(50HZ) Impedance: 4-8Ω Output Power: 2x25W Audio S/N Ratio: ≥98dB Frequency Response: 20-20KHz Infrared Remote Control Distance: 10M Bluetooth Distance: 10M Installation: 86 Standard cable box Colour:Black Material:plastic+metal Package Contents: 1 x Audio Wall Amplifier 1 x Installation Box 1 x Installation Bracket 1 x Installation Screws Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.