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.6. Volume adjustment: 15-level electronic volume adjustment function.7. -off memory function: memorize the state played before the last shutdown.Hardware Parameters:: AC110V-250V(50HZ)Impedance: 4-8Output : 2x15WAudio S Ratio: 98dBFrequency Response: 20-20KHzInfrared Remote Control Distance: 10MBluetooth Distance: 10MProduct Size: 86 x 86 x 10mmInstallation: 86 Standard Colour:blackMaterial:ABSPackage Contents:2 * Bluetooth AmplifierOnly 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.