Wireless Headphones - with microphone, True Wireless earplugs, closed construction, Bluetooth 5.1, supports AAC and SBC, track shuffle, taking calls, with volume control, IPX4 certification, frequency range: 20 Hz-20000 Hz, sensitivity: 117 dB/mW, impedance: 32 Ohm, converter: 10mm, battery life of up to 20 hr(s) (4 hr(s)+16 hr(s))