Description: Low delay, portable adapter can be used as a transmitter or receiver, with hands-free function Suitable for TV, PC, CD player, MP3 / MP4, sound systems transmitting music at home or in the vehicle This car adapter with 3.5mm AUX adapter. Built-in microphone and 250MAH batteries. 2 in 1 design, transfer your TV, PC/laptop or other favorite device to your headphones. Specification: version: 5.0 Support protocol: RX: A2DP, AVRCP, HFP TX: A2DP Working frequency band: 2.402GHz -2.480GHz Power level: power level 2 (Class II) Audio coding: SBC Working current: RX7H distance: >10M (open place) Charging method: Micro USB 5V/0.5A Input/output connection mode: AUX interface Compatible: Android, for IOS system mobile phone, and speakers or earphones supporting A2DP protocol to connect and use Size Chart: Size: approx. 52x52x13mm / 2.05x2.05x0.51 inch Package Includes: 1 Piece Transmitter Receiver 1 Piece Audio Cable 1 Piece USB Cable 1 Piece Manual Note: Please allow 1-3mm measuring deviation due to manual measurement. Due to the different monitor and light effect,the actual color of the item might be slightly different from the color showed on the pictures.Thank you!