The Shut-Off damper is a accessory to regulate the Air-Flow in the ventilation system. Very useful if there are many In-and Out-let points in a planned ventilation system, this helps to bring an equal Air-Flow to every In-take hole or if needed to fully close it. This model lets to mount also a small motor-mechanism to automate the opening of the flap. The damper is constructed from galvanised steel for the collar and lightweight aluminium for the damper blades. Spring loaded for positive closure. Can be mounted horizontally or vertically.