Miniature Double Square For High Precision Machine Tool Set-Up 

All six sides of the tool steel head block of this miniature double square are ground accurate, square, and true. Thumb nut holds 4 inch scale in secure position end-to-end. Works great for high precision miniature machine tool set-up and accurate layout work.

Imperial markings on both sides

Head block is 13mm (1/2") thick x 25mm (1") wide x 62mm (2 3/8") long.