Helix Small Circle Template (37168) 39 circles in 1/64-Inch increments from 1/16-Inch to 1 3/8-Inch Made from dimensionally stable .03-Inch green transparent shatter resistant plastic, overall size 4-Inch x 7 1/4-Inch Designed for use with a 0.5mm lead or pen tip; ink risers on reverse side prevent smudging when using inking pen