[EN 12792-2003, 95]:element inserted into an air distribution system or element of an air distribution system permitting modification of the air resistance of the system, and consequently changing the air flow rate (dampers), or shutting off the air flow completely (valves), or controlling the air flow rate and in addition providing shut-off of the air flow (control valves). Examples of dampers (which can also be found as valves or control valves) are:single leaf damper[EN 12792-2003, 95]:Having the flap centrally mounted or at one end(sometimes one or a combination of this damper is used as diverting element)butterfly damper[EN 12792-2003, 95]:Having two flaps in ‘V’ arrangement.multiple leaf damper[EN 12792-2003, 95]:Having a number of shutters in opposed blade or parallel arrangement.iris damper[EN 12792-2003, 95]:Having sectorised bladeshit and miss damper [EN 12792-2003, 95]:Having two or more slotted slides in parallel arrangement and adjustable against each other.slide damper [EN 12792-2003, 95]:Having a sliding part, which is perpendicular to the direction of the air flow.