Flat Free Tire product of solid, polyurethane foam.Perfect caster for small equipment, carts, etc.Heavy-duty mobility resolution for carts, instruments & equipmentCasters Type: Top plate castersHeavy obligation design4 Swivel castersDurable wheelsDouble bearings and locksTop Plate Size: 7.0 x 5.1cm/ 2.76 x 2.0 inchMounting Height: 7.5cm/ 2.95 inchMounting Hole: 1.1 x 0.8cm/ 0.43 x 0.31 inchLoad Capacity: a hundred and ten lbs (Per wheel)Total Load Capacity: 330 lbs(Counting three PCS when using.)Colour: BlackMaterial: PU, metalSize about: Caster size: 5cmPackage Contents:4* Heavy obligation peak plate swivel castersOnly the above package content, different merchandise usually are not included.Note: Light taking pictures and diversified reveals could cause the color of the thing in the picture a little bit different from the real thing. The size allowed error is +/- 1-3cm.