Lance Center Finding Ruler 18" x 1 3/4". A precision tool, calibrations are on two edges, on one side. This ruler is designed as an aid in finding the center between two points. This will save you time in pattern making, tailoring and crafts. Top edge has a zero point at center and with increments of 32nds of an inch while the bottom edge is a standard ruler calibrated in 16ths. Priced per ruler.