Multifunction button (mfb): you can turn the receiver on or off by long pressing the mfb for 3 seconds. When you have a phone call, you can answer/end the call by short pressing the mfb, you can also reject a call by long pressing the mfb for 3 seconds. While playing music, you play/pause playback by short pressing the mfb. Csr8635 bluetooth chip: the bw-br1 operates on a csr8635 bluetooth chip which provides high-quality sound and wide compatibility with bluetooth devices. The csr8635 chip is compatible with hfp, hsp, a2dp and avrcp protocols. The connection between device and the bw-br1 can operate at a distance of up 30 feet. Bluetooth v4.1: blitzwolf bw-br1 bluetooth receiver uses the bluetooth 4.1 technology, this ensures stable and interference free wireless transmission of audio. With bluetooth v4.1 connecting and reconnecting your devices to the bw-br1 are lighting fast. Bluetooth 4.1 also enables you to connect two devices at the same time. High capacity battery: the blitzwolf bw-br1 built-in 170mah battery provides upto to 8 hours of continuous transmission. Fully charging the battery takes around 1.5 hours. Wide range of uses: you can use the blitzwolf bw-br1 in your car with the 3.5mm to 3.5mm connector or the 3.5mm cable provided you have an aux in mode in your car stereo; you can also use the bw-br1 at home and connect it with your home theater speakers. Once setup with your stereo or speakers, you can then pair your smartphone, tablet, computer, psp or any audio device that supports bluetooth v4.1. Once your device is paired, audio from your device will be streamed wirelessly to your home or car audio system. Note: the blitzwolf bw-br1 bluetooth receiver's operating voltage is 3.3-4.2v, when the internal battery is below this level, or if you have not used it for an extended period of time, it should be charged first. Damage to the battery or the receiver my result if operated on a low voltage. An 18-month warranty: we believe in our products, join blitzwolf to get what you want. We back them all with an 18 months warranty and provide friendly and convenient support. Package includes: 1x bluetooth v4.1 bluetooth music receiver, 1x 3.5mm to 3.5mm connector, 1x 3.5mm audio cable, 1x user manual.