Kaiser Fototechnik 4014 Darkroom Light Filter, red,

Size 9 x 12 cm (3.5 x 4.7 in.), for 4018 darkroom safelight.

4013: Orange, for B&W silver chlorobromide papers

4014: Red, for orthochromatic papers and films and B&W graded papers.

4015: Multigrade?, for variable contrast papers and B&W graded papers