VEMCO scale ruler USA, 9P-1, with metal inserts at both ends to attach the acrylic rule to a Vemco drafting machine. The measuring surface is 12” and the complete ruler is 12.5” in length. One edge is “INCH 1:1 16” or half size to 1/16 inch. The facing edge is “INCH 1:2 32” or full size to 1/32 inch.