The Young Regulator 4040 and 4040P are round, low leakage, dampers. They each provide efficient air flow control in conventional air handling systems where minimal air leakage past the closed damper is critical. A commercial quality shell and sleeve with a 1/2″ plated steel shaft makes these ideal for medium velocity applications and differential pressure applications up to 4″W.C., with a maximum approach velocity of 2,000 feet per minute. Both dampers can be operated by a variety of manual controls or by other manufacturers’ motors. The 4040P comes with a mounting plate for building management controls by others.