Ideal Security Inc. SK7123 Premium Garage Door Rollers 2 inch Nylon & Steel Wheels, 10 Ball-Bearings, 4" stem, 2-Pack, Ultra-Quiet Replacement rollers for residential and commercial garage doors. These are commercial grade rollers, better than the standard OEM rollers included with most garage doors Nylon shells around steel wheels, for the ultimate combination of quiet and durable. 11 ball-bearings per wheel for even smoother operation 1-13/16" wheels for all 2" tracks, the residential standard 3.75" inch stems for standard single-hinge installations