I can do one better on husbands. Mine is a machinist. He made me two sets of rulers one out of alumunin and one of plexiglass. Several are L shaped and all have holes drilled in them to facilitate hanging them up. He also made me several differnt sizes of squares ranging from 2.5 inches up to 6.5 inches. Since he is used to working in 100s of inches I know they are super accurate.