Bluetooth-compatible 5.0 chip is used in this helmet headset, which has high-fidelity stereo sound effect; and it has a power display to remind the power situation and timely charging. A hands-free call function in this helmet headset can really free your hands for safe riding; two 450mAh batteries are built-in to ensure standby and working time. Made from ABS and electronic component material, the product is durable and lightweight. The length of the product is 4.88 cm, the width is 4.88 cm. It is very convenient for motorcycle driving, bicycle cycling, snowboarding, skiing, etc. Item Name: Helmet Headset Material: ABS,Electronic Component BT Version: 5.0 Frequency: 2.402GHz-2.480GHz BT Distance: 10m-20m (Depending On the Environment Around the Device Such As Obstacles) Microphone Transmission Distance: Less Than or Equal to 1m Li-Ion Batteries: 2 x 3.7V 450mAh Batteries Playtime: Less Than or Equal to 16 Hours Charging Voltage: 5V Charging Time: About 3 Hours Standby Time: Less than or Equal to 720 Hours BT Pairing Name: BT23 Features: Noise Reduction, Easy Operation, Wireless Size Details: 4.88cm x 4.88cm/1.92" x 1.92" (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 Helmet Headset 1 x Micro USB Charging Cable 1 x User Manual