WHEEL MATERIAL: Polyurethane Solid. the wheel and the core is one mold - Makes it super heavy duty, an Amazing 200LB Capacity Per Caster Wheel. QUALITY: These wheels are made of precision molded solid polyurethane These polyurethane wheels offer easy roll-ability, floor protection, non-marking and non-conductive performance. Polyurethane resists most chemicals, oils and rejects floor debris. Our industrial wheels are ready for your heavy duty project. FEATURES: These Low Profile Caster Wheels give you the ability to Carry items of very heavy capacity while staying low profile. HEAVY DUTY BEARINGS: Steel structures body is extremely hard wearing and resistant to dirt, Bearing Heavy Duty. SPECIFICATION Rotate 360 degrees Smooth and Silent and Sturdy Capacity: 200lbs each caster wheel Plate Size: 1.9" (48mm) X 2.6" (66mm,) Hole center to hole center:, 1.2"(32mm) x 1.9"(49mm) Mounting hole dimensions: 0.23"(6mm) X 0.32"(8.2mm) Overall Height: 57mm, 2.2" Caster Wheel Diameter: 50mm , 1.5"(40mm) Caster Wheel Width: 1" (27mm) Caster Wheel Material: Polyurethane Caster Wheel Color: Black Ball bearings: Double ball bearings PACKAGE INCLUDES 4 x Caster Wheels (1.5 Inch No Brake)