Feature: 1. You can DIY a for speaker, just need a battery(3.7V to 5V lithium battery, not more than 5V, the regulated power supply is 4.2V to 5V, this product doesn't include battery), two speakers, and a case then you will get a nice for speaker. 2. Output 5W + 5W dualchannel stereo, support USB sound card, no driver, just plug and play. 3. Mini for receiver board updates to for 5.0 version, which is compatible with most mobile phones and for adapters. 4. The maximum transmission distance is about 15 meters, and the power consumption in standby mode is ultralow. Specification: Item Type: Power Amp Module Voltage: 3.7V-5V Current: 1.5A-2A Power: 5W + 5W For: 5.0 Speaker: 4/3W (not included) Material: PC+metal colour: green Package Contents: 2 Amplifier Board 6 x Connection 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.