This set of stem casters features 5" swivel casters with brakes, ideal for worktables, shelving units, and utility carts. The heavy duty stem fits standard 1-5/8" tubing found on many worktable legs with an expandable rubber collar. Hand-tightening a grip nut on the stem expands the rubber. When it's a snug fit in the tubing, you turn the swivel bearing counter-clockwise to expand the rubber even more to tighten the stem inside the leg. The 5" casters have grease-resistant polypropylene wheels with locking side brakes and have a load capacity of 220 Lbs. per caster. They operate in a temperature range of 14ºF to 212ºF. The set includes four stem casters.