1. No manual operation is required, incoming calls are automatically answered to the safety of cyclists; 2. Waterproof button design, no fear of wind and rain! 3. The latest Bluetooth V5.0 chip, high-fidelity stereo sound, clear, stable and continuous calls; 4. Ultra-low power consumption, 19 hours of continuous music playback (250mAh battery); 5. The transmission rate is fast and stable, with an unobstructed transmission distance of more than 20 meters and up to 50 meters; 6. Built-in high-sensitivity microphone and equipped with windproof sponge cover; 7. There are voice prompts for power on, power off, pairing success, low battery, maximum volume, etc.; 8. The iOS system can display battery power and activate SIRI intelligent voice assistant; 9. It can be used with most motorcycle helmets on the market and can be DIY installed, which is simple and convenient. parameter: Bluetooth specifications: V5.0+//A2DP/AVRCP/HFP Frequency range: 2.4026GHz-2.480GHz Transmission distance: more than 20 meters Sound channel: stereo Speaker parameters: 30 ohm/30mm Speaker power: 30 mW*2 Signal-to-noise ratio: 110dB Functions: Previous song, song, volume up, volume down, play, pause, answer calls, make calls, activate SIRI, microphone intercom Lithium battery: 3.7V/250mAh Play time: about 16 hours Talk time: about 16 hours Standby time: about 700 hours Charging time: about 2.5 hours Colour:black Material:plastic Package Contents: 1 set of motorcycle helmet bluetooth headphones Only 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.