H D Metal Casters for #7026E (Set 4) Ultrasound Lotions Gels Accs * Complete with four waveforms Nerve Sensory Evaluator Access * Complete with four waveforms the unit gives you and your patients the flexibility to treat a variety of musculoskeletal issues Easily opens and folds * Folds flat for convenient storage and transportation * 16 Replacement Caster 3 x 1 1 4 * HD Casters Have Threaded Stem For Extra Security And Safety * All Single Wheel Castes Come With Removable Bolt And Locknut Allowing Disassemlby For Easy Cleaning And Removal Of Build Up Grime Thread Or Anything Else That Your Wheel Picks Up During Normal Usage * This Caster System Will Add Longevity To Your Casters * Swivel: Double Ball Bearing With Hardened Raceways For Extra Strength * Cover: Helps Protect Swivel Bearings * Construction: Heavy Guage Cold Rolled Steel Formed For Strength