Brand new, unused, a set of four (4) machined rollers/wheels, compatible with Total Gym replacements. The bearing hole diameter is approximately 5/16 inch. All bearings are included. Compatible with 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 robust engineering plastic. This means your gym equipment can quickly get back up and running and achieve maximum efficiency. The rollers are designed with softer, quieter materials. Laboratory and gym tested and approved. Stronger, quieter, and more durable than original and other aftermarket products! Manufactured and tested to perform as well as original OEM parts, but at a more affordable price than comparable original parts from the manufacturer. Buy with confidence.