This caster has a built-in dust ring, 3.0mm thick bottom plate, increased load, and is not easy to deform. Widened 3.3cm polyurethane wheel, more stable grip, directional wheel, universal wheel, brake wheel, a variety of styles for you Choice, you can freely mix and match Features: New polyurethane material, upgraded widened galvanized bracket, thickened bottom plate, widened wheel, high speed disassemble bearing, built-in dustproof ring, strong load bearing, easy to install, environmentally friendly material, strong wear-resistant, ultra-quiet, shockproof Strong, 360 degree free rotation Free combination of casters, can be freely matched according to your needs A: directional wheel x4 B: universal wheel x4 C: brake wheel x4 D: 2x directional wheel + 2x universal wheel E: 2x directional wheel + 2x brake wheel F: 2x universal wheel + 2x brake wheel Product Name: Heavy Duty Castors Specifications: 3 inches, 4 inches, 5 inches Type: universal wheel, directional wheel, brake wheel Material: new polyurethane, galvanized bracket Bearing capacity: single wheel bearing weight of about 300KG Applicable: heavy industrial casters such as scaffolding wheels, flatbeds, trolleys, etc. note: 1. This product is only for casters, does not contain other products, depending on the actual product. 2. The size of the product is measured by hand and may have some error. This is normal. 3. Due to the light of the display, the color of the picture and the object may have a certain color difference, please understand. 4.1-2 days delivery, arrive 15-25 days. If you have any questions, please contact us in time, we will solve any problems related to the products in time.