Anytime Tools 10 pairs MACHINIST THIN PARALLEL JIG BLOCK BAR TOOL SET Made of high grade alloy steel, hardened and ground. 2 holes in each parallel. 10 1/8" Thin matched pairs in set. +/- .0002 Parallelism in height. High quality precision ground alloy Hardness: 54-58 HRC .Measurements: 6" long x 1/8" thick Two holes in each bar. Increments in 1/8" from 1/2" to 1-5/8". Set includes a pair of each height: 1/2, 5/8, 3/4, 7/8, 1, 1-1/8, 1-1/4, 1-3/8, 1-1/2 and 1-5/8