This Fletcher 120 Degree Replacement Wheel Unit quality wheel assembly has a steel wheel revolving on a hardened steel axle within a hardened steel shield. This wheel is designed for cutting thin glass and fit Cat. No. HDG15 Heavy-Duty Hand Glass Cutters, 3000 and 8400 Series Machines, and CircleMateT Cutters. The steel casing is also hardened for long service life and superior strength. Steel Wheel Units are sold in packages of 10.