Promate Concord Headphones, Powerful HD Stereo Wireless Headphone with Active Noise Cancellation: Technical Specifications:Bluetooth Version: V5.3 Bluetooth Frequency: 2.4 - 2.48GHzImpedance: 32Ω ,Frequency: 20Hz-20KHz , Sensitivity: 105dB±3dB, Reduction Noise frequency: -26dbCharging Time: 1.5hrs,  Battery Capacity: 500mAh,Battery Type: Li-PolymerInput Port type: USB-CFeatur