Kodak 3 x 3" #2E Pale Yellow Optical Wratten 2 Filter is an industry-standard filter that just got better. With the same spectral response and color as current Wratten Gelatin Filters, Kodak Wratten 2 Optical Filters offer several improvements.
The #2E absorbs ultraviolet radiation. This weak yellow filter is used when a #2B doesn't provide enough in black and white photography. Should more contrast be desired, try a higher grade filter such as 2B, 9, 12 or 15.