Bluetooth Receiver. Features: Using a new Bluetooth chip architecture, the BTR1 supports Bluetooth 4.2 with an effective transmission distance of up to 10 meters as well as the SBC, AAC and aptX audio formats. The BTR1 also supports Bluetooth voice calls with its built-in omnidirectional microphone, that captures audio with equally high quality as that typically used in phones. The built-in rechargeable lithium battery can be fully charged in just 2 hours, and can last more than 8 hours when being used. The BTR1 comes in a sleek aluminum alloy body finished in black, giving robust yet attractive look. The BTR1 supports connecting with two devices at the same time, giving you more ways to play and listen. Compatible with Android and iOS devices, as well as TRS and TRRS headphones. Specs: Headphone Output: 3.5 mm stereo jack. Frequency Response: 20～20 kHz. Including USB charging cable. Dimensions: 24 x 50 x 11.6 mm. Weight: 20.5 g.