Beyution 525 Metal Bluetooth headphones Hi-Fi Over-ear Stereo Bluetooth Headphones Built in Mic-phone talk with phone or listen music clearly, built Noise cancellation technology with Retail package New Metal(not Plastic) HiFi Bluetooth Headphone Headphones headset for Cell Phone/Laptop/PC/Tablet HiFi - Best Audio Performance - Stereo - Wireless Bluetooth 33 feet distance - Over the head Built-in microphone Allows clear Phone communication; Enables use as a headset. Music and phone controls ensure ease of use Built-in rechargeable lithium-polymer battery With Li-battery enables up to 8-9 hours of talk time or audio playback, Standby time up to 180 hours. Passive noise reduction Up to 15dB blocks background sounds for an immersive listening experience. Noise Blackout with dual microphone technology promotes optimal call quality.