AUDIO Frequency response: 20 Hz ~ 20 kHz Driver diameter: 10 mm Maximum power: 5 mW Design: in-ear Type: dynamic Impedance: 16 ohms CONNECTIVITY Bluetooth 5.0 Frequency band: 2.4 GHz Maximum output power: Supported Bluetooth protocols: HFP / A2DP / AVRCP / AVCTP profiles Up to 20 m range True Wireless function with auto-pairing Hands-free function Volume control Playback control MICROPHONE Type: built-in Sensitivity: -42 dB 3 dB (@1 kHz) BATTERY Earbuds: Capacity: 40 mAh (each earbud) Type: lithium polymer Battery life at medium volume: 5 hours* Charging time: 1 hour Charging method: charging case Charging case: Capacity: 300 mA Type: lithium polymer Extra battery life: 15 hours Charging method: microUSB type-B * This value is approximate. The battery life depends on the selected volume and the type of music. SIZE AND WEIGHT Earbud weight: 4 g Earbud size: 2.4 x 2.3 x 2.6 cm Case weight (without earbuds): 28 g Case size: 7.3 x 4 x 2.9 cm 7,3 x 4 x 2,9 cm