The advanced CSR Bluetooth-compatible chipset and the embedded headphone amplifier provide a better phone call and stereo experience. Its delicate, compact and waterproof design make it a good companion for your cycling trips. It is made of good quality ABS material, durable to use. The length of this product is 8.5cm, the width is 5cm and the height is 2cm. In order to make riding safer and easier, the bluetooth-compatible helmet headset is specially designed for mobile phone calls, stereo music playback and remote operation of FM radio. Item Name: Headphone Material: ABS Color: Blue Model: QTB35 Bluetooth-compatible Chip Version: 5.0 CSR8635 Introduction to BT: A2DP, ACRCP Battery Capacity: 450mAh (Included) Charging Voltage/Current: DV 5V / 190mA Frequency: 2.4GHz Amplifier: HT4832SQ Working Time: about 10 Hours Mobile Phone Distance: 50 Meters Features: Waterproof, Portable, Stable Transmission Size Details: 8.5cm x 5cm x 2cm/3.35" x 1.97" x 0.79" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Headset 1 x MIC and Speaker 2 x Helmet Inner Fastener Tape 1 x Fixed Folder 1 x Screwdriver 2 x Screw 1 x Charging Cable 1 x User Manual Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin