Wireless Headphones Hands-free Calling Bluetooth Wireless Wired Red Color Variations Red / Black [Compatible Devices] Compatible with various devices equipped with Bluetooth functionality. [Main Specifications] Bluetooth Standard: Bluetooth 5.0 Power Input: DC 5V / 80mA Bluetooth Profiles: A2DP 1.2, AVRCP 1.0, HSP, HSF 1.5 Continuous Talk Time: Approximately 10 hours Continuous Music Playback Time: Approximately 8 hours Continuous Standby Time: Approximately 250 hours Charging Time: Approximately 1.5 hours Weight: Approximately 180 g Wired and Wireless Dual Use: Includes a 3.5mm audio cable, can be used as wired headphones. Battery Capacity: Built-in rechargeable lithium-ion 400mA battery Playback Frequency Range: 20 Hz 〜 20,000 Hz Range: Up to approximately 10M (without obstacles) Carrier Frequency: 2.402 GHz 〜 2.480 GHz Distortion Rate: Less than 1% (1 kHz) [How to Adjust Volume] ■ Volume +: Long press the [v+] button ■ Volume -: Long press the [v-] button [Included Items] Headphone Body Micro USB Cable (approx. 80 cm) Connection Cable (approx. 1 m) Simple Japanese and English Instruction Manual