4-Inch Thermoplastic Swivel Plate Caster/ Brake BestAir Extreme durability and impact resistance

Extreme durability and impact resistance for up to 50X longer life versus standard bits

PUMP - Make sure handle is screwed on tightly or the bottle will not pressurize

Rim tempered end

No batteries required

General-purpose

4-Inch Thermoplastic Swivel Plate Caster/ Brake BestAir Extreme durability and impact resistance4", Gray, TPR, Swivel Plate Caster With Side Grip Brake, 246 Lb Load Capacity, Quiet & Non Marking, Effective Gripping Action Across The Tread Prevents Wheel From Rolling, Gray Thermoplastic Rubber Tread On Black Polypropylene Hubs, Offers A Soft, Quiet & Cushioned Ride, Excellent Flat Spot Resistance & Is Resistant To A Broad Range Of Chemicals, Acids, Solvents & Detergents, Bulk.