1. Working voltage: 3.7-5V DC 2. Size :40x20x12mm(length x width x height) 3. Power :5W 4. Bluetooth module operation: Turn on the Bluetooth of the mobile phone, scan the device, find "JZ-B5W2"and click to connect 5. This Bluetooth is version 4.2. Compatible with all mobile phones and Bluetooth adapters on the market. The transmission distance in open land is about 15 meters. Automatically connect back to paired devices and play music automatically. 6. USB sound card, no drive, plug and play (under normal lithium battery power supply). Colour:red Material:ABS Due to different batches, there may be differences in product appearance and printed text, which will not affect use Package Contents: 10 * Power Amplifier Board Module 10 * Cable 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.