Wireless Headphones Stereo Bluetooth Headset Noise Cancelling Over Ear With Mic Specification: Bluetooth Version: V5.0 Support Bluetooth Mode: A2DP 1.2, AVRCP 1.0, HSP, HSF 1.5 Frequency: 2.402-2.480GHZ, 2.4G ISM band RF Performance: receiver sensitivity: -84dBm; transmit power up to 4dBm Frequency Response: 20 Hz - 20 KHz Signal to Noise Ratio (SNR): 70Db; Total Harmonic Distortion Rate (THD) 0.1% Power Indicator: Red and blue lights alternately flashing Headset Charging: rechargeable 400MAH lithium battery Charging Port: Mini 5-pin USB charging interface Normal Charging Time: 2.5 hours Talk Time: up to 10 hours Standby Time: up to 20 Days Operating Temperature: -20? - 55? Other Features: support status indicator, charge indicator display