The K812 is an open-back, over-ear reference headphone aimed at music professionals who mix, master and produce. It uses a 53 mm transducer, the largest the maker has fitted to a headphone, driven by a 1.5 tesla magnet system and a lightweight two-layer copper-covered aluminium voice coil. The stated frequency range runs from 5 Hz to 54 kHz.

For long sessions the design uses an open mesh headband and 3D-shaped, slow-retention ear pads, which are replaceable. The headphones do not fold. Rated impedance is 36 ohms, sensitivity is 110 dB SPL/V at 1 kHz and maximum input power is 300 mW. Weight is 390 g without the cable.

The cable is detachable and 3 m long. It ends in a gold-finished 3.5 mm stereo plug, with a screw-on 6.3 mm adapter for studio amplifiers. The set includes a premium headphone stand. Listed uses are studio mixing, hi-fi listening and mobile devices.