Fluorescent Scale in inches and centimeters. This metric/english plastic ruler is printed with a pink phosphorescent ink that glows in the dark. It is most useful for all fluorescent viewing and fluorescent photographic work. The scale will fluoresce visibly upon illumination with ultraviolet light and serves as a measure of nucleic acid mobility. The scale is 0 to 6" with 1/16" increments on one edge and 0 to 15 cm with 1mm increments on the other.