CHARACTERISTICS: Volume control dampers 50 mm pitch. ARTICLE DESCRIPTION: SRC50-P: opposed blade damper with pin for servo-motor (standard). SRC50-C: opposed blade damper with manual control. CONSTRUCTION: Galvanized steel frame. Extruded alluminium blades. FIXING: By bolts on flanges corners. DETAILS: Drive: Counter rotating movement by train of gear wheels made of nylon, driven by manual control or servomotor.