Heavy-duty caster: 1-1/4" wide ball-bearing caster, with TPU (urethane) tread, rated at 250 lb dynamic load per caster. The wide wheel and larger swivel improves rolling on rough surfaces. The urethane tread is more chemical resistant and more resistant to picking up metal chips and rivets. (Please note: replacing the standard casters with the heavy-duty casters will increase the AeroCreeper height by ⅝” with the 3" casters, 1 ⅝” with the 4” casters and 2 ⅝” with the 5” casters.)
This caster has a 1/2" diameter stem. To replace casters with 3/8" stem (pre-Oct 2018 models), the holes will need to be enlarged.