Made of hardened and tempered steel. Satin Chrome Finish. Made in USA England. 4R graduation shows 32nds, 64ths, 8ths, 16ths. 16R graduation shows 32nds, 64ths, 50ths, 100ths. E/M graduation shows 32nds, 64ths, 1mm, 1/2mm. 3R graduation shows 32nds, 64ths, 10ths, 50ths. 5R graduation shows 32nds, 64ths, 10ths, 100ths