The Radius Gauge, developed by Bocchi, comes with steel blades. The unit is available in 3 different ranges such as 1 mm to 3 mm in step of 0.25 mm, 3 mm to 19.5 mm in step of 0.50 mm, and 19.5 mm to 25 mm in step of 1.00 mm. It is also available in various radius sizes from 1 mm to 25 mm.