6" x 3" Phenolic Wheel Rigid Caster Extreme Duty - 2000 lbs. capacity6" x 3" Phenolic Wheel Extreme Duty Rigid Caster The Phenolic wheel is made of phenolic resin and macerated canvas, which provides smooth rolling and resistance to extreme temperature shifts. Phenolic wheels are resistant to oils, greases, and some liquids, but they should not be used on rough surfaces or wet environments. Tread & Core: Phenolic resin with Macerated Canvas Bearing: Roller Bearing Rig: Drop forged steel rigid caster, 6 1 4" x 7 1 2"