New and unused set of four (4) machined wheels/rollers compatible with Total Gym Replacement. The bearing hole diameter is approximately 5/16 inch. All bearings are included. Fits models 1000, 1100, 1400, 1500, 1600, 1700, 1800, 1900, Achiever, Core, Elite, Force, Gold, Gold Plus, Max, Platinum, Platinum Plus, Power Platinum, Premiere, Pro, Supra, Supreme, Ultima, Ultra, X-Force, and XLi. Our rollers are made from high-quality solid engineering plastic material. This means your gym will be up and running quickly and operating at maximum efficiency. The wheels are designed with smoother and quieter materials. Lab and gym tested and approved. STRONGER, QUIETER, and LASTS LONGER than original and all other aftermarket products!!! Manufactured and tested to perform as well as original OEM parts but at a better value than a comparable original equipment part. Please feel confident with your purchase.