"Rigid 4 x 1-1/2 caster, mold on urethane"
"Rigid 4 caster with 4 x 2"" urethane wheel."
Rigid 4 caster with 4 x 2 RollXWow wheel.
Rigid 4 caster with 4 x 2 moldon rubber wheel
Rigid 4 caster with 4 x 2 phenolic wheel
"Rigid 4 X 1 1/4"" Pro wheel BB"
