Comfort and Secure, Fit for All - Day Wearing With 2 large 16.2mm dynamic speaker drivers, the product can deliver sooth high pitch and deep powerful bass. Low frequency is reconstructed in real time to recreate a natural and live sound. With 2 built - in microphones and beamforming algorithm, you can have clear phone conversation at any time. Designed with special acoustic cavity for no sound leakage to protect your privacy. You can customize sound character to your personal preference - Classic or Bass Boost. The headphone offers up to 17 hours playtime when fully charged, and a 5 hours playtime in just 15 minutes charging. IP55 - rated dust and splash resistance for long durability.