1. The built-in battery lasts up to 16 hours.2. Keep pairing with 2 wireless devices at the same time.3. The built-in microphone can be used to answer hands-free calls.4. The latest noise-cancelling technology provides excellent call quality.5. Compatible with most wireless-enabled devices such as smartphones, tablets, laptop and computer.Pair with phone/mp3/tablet etc, turn your old car stereo/house stereo/3.5mm wireless wired headphones.Wireless version: 5.0Frequency range: 2.4GHzOutput power class: class2Wireless Mode: HFP//A2DP/AVRCPWireless Range: than 33 feetBattery: 250mahWorking current: 15-20MACharging voltage: DC/5vCharging current: 150MAProduct size: about 50x50x20mmColour:As ShownMaterial:PlasticPackage Contents:1 * Wireless Receiver1 * 3.5mm Male to Male Connector1 * 3.5mm Audio Cable1 * Type-C Charging Cable1 * English User ManualOnly 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.