Made for my Irwin chisel set including 2",1 ½", 1 ¼", 1", ¾", ½", 3/8" and ¼" chisels which are also labelled as 7, 10, 13, 19, 25, 31, 38 and 51mm. I've Added an unlabelled version for metric compatability. There should be at least 2mm leeway either side is trying to fit different sized chisels. I'm very pleased with the model, the chisels are easy to get in and out and it is very sturdy which was my main concern when designing it.