Light-tight louver to provide an inlet for fresh air for darkroom ventilation fans. The DV-99 is similar to the L-1212 louver , but is smaller in size and can be installed in an 8"x 8" opening. It can be used with darkroom fans smaller than the Doran model A-1212, or in situations where installation of an L-1212 louver would be difficult or impractical, or to direct incoming air across more than one area, two or three DV-99 louvers can be installed in place of one L-1212. 9-7/8"x 9-7/8"x 1¾" exterior dimensions.