Product Parameters:Bluetooth version: V4.0Answer: Auto / ManualFrequency: 180-2000KHzRange: 10 to 20 m (depending on the surrounding environment such as an obstacle)Microphone transmission distance: ≤1 mLithium-ion battery: 3.7V / 180mAPlaying time: ≤8 hoursCharging voltage: 5VNoise: 80DBModel Number: BT10Accessories type: Helmet HeadsetMaterial: ABSPackage weight: 0.255 kgProduct size (L x W x H): 19.00 x 6.00 x 2.80 cm / 7.48 x 2.36 x 1.1 inchesPackage size (L x W x H): 23.50 x 10.00 x 4.70 cm / 9.25 x 3.94 x 1.85 inchesPackage Contents: 1 x Helmet Headset, 1 x Charging Cable, 1 x Manual, 2 x Velcro