The YYK-526 is an ergonomic, ultra-lightweight wireless headset featuring Bluetooth V5.4. I purchased this current model about a month ago. Please look up the detailed specifications. I opened it and charged it, but I didn't end up using it. - Model: YYK-526 - Bluetooth Version: V5.4+EDR - Battery Capacity (Earphones): 60mAh - Battery Capacity (Charging Case): 500mAh - Design: Ergonomic design - Weight: Ultra-lightweight - Charging Method: USB charging - Display: Battery level indicator Thank you for viewing.