1.Sold as a set of 4 2.Load rating for the set: 300KG 3.This casters will add approximately 6" to the heigh of the posts. 1.Non-marking polyurethane casters, 4" diameter2. Sold as a set of 4: Two swivel casters plus twoswivel with brake casters 3. Load rating for the set: 400 KG4. Casters are threaded and are to be used with standard posts5.Use stem casters to add shelving mobility and increase ...