Wireless Headphones - with microphone, True Wireless earplugs, closed construction, Bluetooth 5.1, taking calls, IPX4 certification, frequency range: 20 Hz-20000 Hz, sensitivity: 94 dB/mW, impedance: 16 Ohm, converter: 8mm, battery life of up to 4 hr(s) (1,5 hr(s)+2,5 hr(s))