Our individually-sold 5" polyurethane threaded caster is quite convenient if you need an odd number or only require a few replacements for your wire shelving.They are compatible with Shelving Inc. brand posts only. If you have another brand, please use thesestem casters. Sold individually, available in 4-packhere Best for cold and hot environments and smooth indoor surfaces Bolt with 12 threads per inch screws into bottom of Shelving Inc. brand 1"dia post Swivels 360 degrees for easy steering Step-lock brake prevents movement Resists chemicals, grease, and oil Holds 300 lbs and 1,200 lbs per set of four For stability, not recommended for use with 8"d wire shelving