The Atomuffler® Relief Valve Muffler includes all the outstanding features of the industry-standard Atomuffler plus an added relief valve. Superior design and construction provides a low-cost, effective method of eliminating annoying, distracting noise emitted from air-operated devices. The unique relief valve equalizes pressure by detecting any outflow deviation, responding to the pressure differential and opening up to compensate for outflow demands. Relief Valve Mufflers are ideal for applications where uninterrupted continuous outflow is imperative.