Features: BT V4.1 + EDR provides a more stable and smooth connection. Hi-Fi headphone offers premium sound performance. Support hands-free calling, truly releases your hands and ensures your safety while driving. Support for answering, rejecting, hanging up and redialing phone functions. Built-in rechargeable Li-ion battery, working hours up to 8 hours, standby time up to 160 hours. 4.0 type of CSR BT chip, Hi-Fi headset. Voice prompt function, it will give sound like "Power on", "Pairing", "Connected", and make it easy to set and process the operation. Support for iOS to display the power and to know when to charge. In power save mode, it will turn off automatically after 5 minutes if no working device paired. DIY design, available to be detachable when you want. The low power warning lets you know that the battery is not enough and needs to be recharged. The sound reminder function makes it easy to set up the device based on the sound reminder. Magic tape design lets you install and detach headphone anytime and anywhere. Specification: BT Version: 4.1 + EDR, CSR Frequency: 2.402GHz-2.480GHZ Transmission Range: 10-15 meters / 32.8-49.2ft(Depending on the equipment) Microphone Transmission Distance: ≤1m Li-ion Battery: 3.7V/500mAH Playback Time: ≤15 hours Charging Voltage: 5V Charging Time: ≤3 hour Delay: ≤ 240 hours BT Name: BT12 Color: Black Weight: Approx. 180g / 6.3 oz Package list: 1 * Helmet BT Headset 1 * Charging Cable 1 * User Manual .