Shars Tool 81 Piece Steel Precision Gage Block Set with Nist Traceable Certificate: .1001" to .1009".101 to .149".05" to .95",1";2" 9 blocks: .1001-.1009" in .0001" steps 49 Blocks: .101-.149" in .001" Steps 19 Blocks: .050-.950" in .050 steps 4 Blocks: 1-4" in 1" steps Accuracy: +/- .000050"