Individually sold, these rubber stem casters are convenient when you only need a certain amount. Whether it's a replacement or for a wire shelving unit without four posts, this accessory is here to help enhance the functionality of your storage. Sold individually, available in 4-pack here Compatible with most 1" diameter posts Best for rough surfaces Stem acts as plug and fits into post's bottom Absorbs bumps and shocks Rotates 360 degrees for easy maneuvering Optional step-lock brake to control movement Won't leave marks on floor For stability, not recommended for use with 8"d wire shelving Shipping: Next Business Day