The 66905 Arc Lamp Housing is not just an aluminum enclosure for the lamp, it holds the ignitor, condensing optics, rear reflector and lamp cooling fan. This version was designed for 50 to 500 Watt Hg, Xe and Hg(Xe) DC arc lamps. It uses a F/0.7 Four Element Fused Silica Aspherab condenser for a 2.7 inch (69 mm) diameter collimated beam at the 3 Inch Series output flange. You can simply change the socket adapter and you can interchange between lamp types and wattages, within the appropriate housing family. The socket adapter holds the lamp at the proper optical height for the rear reflector and condenser. To optimize the position and to compensate for lamp to lamp variations, we provide rear reflector and lamp adjusters. These lamp housings include a number of safety features to prevent lamp damage and accidental exposure. A door interlock prohibits the operation of the lamp while the door is open; a temperature sensor monitors the lamp’s operating temperature and controls the cooling fan accordingly.