Feature:1. 2 People Full Duplex: This wireless helmet headphone supports 6 person pairing, 1 to 5 switching intercom, 2 people full duplex.2. Stable Performance: 5.1 chip, connection distance 10m / 33ft. IP65 waterproof, windproof and anti noise.3. Call Distance: Up to 1200m / 3937ft call distance (barrier free), generally used in the field to a distance of 600‑800m / 1968‑2624ft.4. Automatic Answering Phone: The automatic answering phone function keeps you undisturbed while riding.5. Powerful Functions: Built in lithium battery 2 x 850mAh (included), 260h standby and 29h working time.How to Use:Bluetooth Pairing:1. Press and hold the motorcycle button to turn it on2. The mobile phone searches for Bluetooth pairing successfully, others see the manualSpecification:Item Type: Motorcycle Helmet HeadsetMaterial: ABSBluetooth Protocol: 5.1Intercom Distance: Up To 800m / 2624ftBluetooth Connection Distance: 10m / 33ftWaterproof Grade: IP65Intercom Time: 29hStandby Time: 260hCharging Time: 3hBuilt in Lithium Battery: 2 x 850mAh (included) Package List:2 x Host2 x Headphones1 x Manual2 x USB Cable2 x Screw Clip2 x Hook & Loop Clip8 x Hook & Loop4 x Screw1 x Wrench