Listing is for four (4) Service Caster Replacement Nobles/Tennant Scrubber Bumper Guide Wheels. These 3” x 7/8” non-marking and non-marring floor safe gray thermoplastic rubber wheels are safe for all floors. 5/16” metal spanner bushings included. When searching for a reliable and durable replacement wheel for the following machines; Nobles/Tennant SS5, Nobles/Tennant R3, Nobles/Tennant T12, Nobles/Tennant Speed Scrub 3301, Nobles/Tennant Speed Scrub 2701, Nobles/Tennant Speed Scrub 2601, Nobles/Tennant Speed Scrub 2401, Nobles/Tennant T500/T500e, Nobles/Tennant T7AMR, Nobles/Tennant 5680, Nobles/Tennant 5700, Nobles/Tennant T500 and Windsor Saber Cutter, consider Service Caster's Scrubber Bumper Guide Wheel replacements. The non-marking, non-marring thermoplastic rubber tread performs especially well on hard surfaces such as concrete, tile, and wood. These wheels are perfect replacement wheels for a number of machines. Service Caster is unsurpassed in quality, reliability, and excellent customer service. Count on us to move you forward.