Volkano Aquarius Series Wireless Earbuds with Charging Case VK 1131 BK Installed RAM_2 GB ZenScreen MB16QHG has passed stringent ZenScreen MB16QHG has passed stringent performance tests and is certified by TÜV Rheinland laboratories these durable support columns create additional clearance beneath the machine 0 Wireless Range Up to 10 m Driver Size 8 mm Frequency Response 20 Hz–20 kHz Sensitivity 90 dB Impedance 16 ohms Earbud Battery 50 mAh per earbud Playback Time Approximately 4–5 hours per charge Total Playtime with Charging Case Up to 12 hours Charging Case Battery 300 mAh Case Recharges Approximately 2–3 Charging Time Approximately 1 True wireless in ear design removes the need for a cable between the earbuds