ANC Active Noise Cancelling Bluetooth headphones 5.3

*Product Type: Head-mounted / Over-ear
*Bluetooth version: V5.3
*Receiving frequency range: 2.402GHZ-2.480GHZ
*Frequency response: 20HZ-20KHZ
*Effective receiving distance: about 30 meters
*Music playback: true stereo, good sound quality
*Music playback time: about 40 hours
*Talk time: about 40 hours
*Standby time: about 2000 hours
*Lithium polymer battery: 3.7V/400MAH. With protective plate
*Charging time: about 2 hours
*Speaker specifications: ?40MM 32 noise reduction
*Audio output power: 25MW*2
*Microphone: 40DB 2
*Signal-to-noise ratio: >95DB
*Active noise reduction depth: 20-22DB
*Noise reduction bandwidth: 50-800HZ
*Noise reduction master: T
*Working temperature: -20-60 CDEGREE