Charge limit voltage:5.25 V Charging current:300mA Working current:RX mode: 32mA TX mode: 65mA Shutdown current:20uA Charging time:about 45 minutes Working hours: RX mode: About 8 hours TX mode: about 6 hours Battery capacity:200mAh Wireless sound processing:With technology and the Advance Audio Distribution Profile (A2DP) function Wireless frequency:2.402 to 2.480 GHz Wireless transmission distance: about 10M Effective range of Wireless microphone:0.5 to 2 m (A 3.5 metal adapter is included by default. If you need a 3.5 audio cable, you need to purchase it yourself.) Colour:Gray Material:ABS Package Contents: 1 * Audio receiver transmitter 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.