DGK 4N6 Set of 5 Forensic Ruler ABFO Scales Inches and Metric for Evidence Crime Scene and Bite Mark Photomacrographic Photography SALE PRICE! - Forensic ruler ABFO type with centimeter and inch markings top, side, and inside L-shape Useful for forensic and crime scene photography as well as bite mark and skin injury documentation Multiple perspective circles to compensate for distortion from oblique camera angles Chromatic skin color reference scale and 11 step grayscales. Millimeter markings accurate to 0.5mm or better Set of 5 cards. Printed on heavy card stock. Instructions included. Overall size is 5" by 7" (12.7 x 17.8 cm).