With Sound-Activated Compression (SAC) and Adjustable-Frequency Tuning (AFT), Walker’s Muffs not only compress loud noises to safe levels, but also permit you to adjust frequencies for personal needs. Muffs have 50db of power with a maximum output of 110db, and offer a NRR of 24db. Specially contoured shape eliminates interference when shouldering a gun. The Quad Muffs boast a front and rear high-frequency-response microphone on each earcup for unequalled, stereo-like surround sound. Muffs also sport individual volume controls and are powered by two 1.5-volt batteries (included). Colour: Black.