ZEALOT B20 can be used both wired (via the 3.5mm audio cable) and wireless (via ). With the high-quality microphone, the headset supports hands-free calls. Its artificial protein leather of earmuffs simulated to human skin texture, giving you long-time comfort.    Features: Connection:With function, easy to pair with almost all the BT-enabled audio devices, freely to enjoy wireless music and HD hands-free calls.Stereo sound quality:40mm dynamic drivers transmit high fidelity and powerful bass, bringing great sound effect, just immersing in the music world.Line-in function:Connect to the music players (such as, MP3 / MP4, etc) without function via the included 3.5mm cable.Long Battery Life:Built-in 400mAh rechargeable battery lasts up to 10 hours of music playing time and 300 hours of standby time per charge cycle.Ergonomic Design:Foldable and adjustable headband length, soft leather ear cushion, comfortable to wear and easy for storage.  Specifications:Brand: ZEALOTModel Number: B20 version: 4.0Support Profiles: HSP, HFP, A2DP, AVRCPTransmission Distance: up to 10m (no obstacle)Frequency Responce: 20-20KHzResistance: 32ohmSensitivity: 78±3dbSNR: ≥98dBMicrophone: Built-inPlug Type: 3.5mm Audio PortBattery Capacity: 400mAhMusic Playing Time: about 10 hours (depends on the volume)Talk Time: about 8 hoursStandby Time: about 300 hours Time: 1-2 hours Voltage: DC 5VColor: Black, Black with Gold, Black with Silver, White with Blue (Optional)Main Item Size: 18.0 * 16.4 * 8.0cm / 7.08 * 6.45 * 3.14inItem Weight: 206g / 7.26ozPackage Size: 19.4 * 15.2 * 8.9cm / 7.63 * 5.98 * 3.50inPackage Weight: 410g / 14.46ozPackage List:1 * Headset1 * USB Cable1 * 3.5mm Audio Cable1 * User Manual (English / Chinese)