On-Ear Headphones. Features: Bluetooth wireless technology with mic and controls built into the earcup for answering/ending calls, controlling music & video playback and adjusting volume on connected devices. Internal battery provides up to 40 hours of continuous use (1000 hours on standby) on a full charge. Headphones fold flat for easy transport. Includes 30 cm USB charging cable. Lightweight earpads rest comfortably on the ears and provide good sound isolation. Specs: Driver Diameter: 40 mm. Frequency Response: 5 – 32,000 Hz. Sensitivity: 102 dB/mW. Impedance: 32 Ohms. Weight: 190 g. Colour: Black.