OLS bubble tight isolation damper is designed to pressure rating of 2.5, 3, 4.5 and 7.5 kPa with blade deflection criteria of 1/360 of blade dimension during pressure test. The damper is bubble tight with respect to internal and external leakages. Pressure loss is very low. For our dampers, the operator can be manual, electric or pneumatic actuator. Balancing damper may be provided with lever type or handwheel manual gear operator.