Comfortable over-ear headphones with active noise cancelling technology. You can choose to use the headphones without the ANC function, but simply flick the ANC button should you wish to suppress external sounds, for example when travelling on an aeroplane. Branding can be provided on the aluminium plates of the ear cups, or on the EVA case. Headphones: 18.5 ( l ) x 17 ( w ) x 8 ( h ) cm aluminium, ABS & PU case: 18.5 ( l ) x 14 ( w ) x 8 ( h ) cm EVA Bluetooth version 5.3 10 metre visible distance built-in microphone supports call pick-up 400mAh lithium battery playback time: approximately 15 hours for ANC mode ; 20 hours for Bluetooth only mode active noise cancelling: 20db noise cancelling frequency range: 20Hz – 20kHz sensitivity: 115dB type-C charging port input: 4.75 – 5.25V includes EVA case packaged in a Swiss Cougar gift box