CasterMaster 3X3 Square Rubber Furniture Caster Cups with Anti-Sliding Floor Grip (Set of 4) CasterMaster Caster Cups protect hardwood, ceramic tile, linoleum, and floors surface from indentations from bedroom or home furniture. Rubber CasterMaster Caster Cups have also been known to be a great support for both upright and grand piano's in homes and bedrooms. Incredibly easy to use. Simply slide the caster cups underneath the furniture leg and let the casters do what they are designed to do. These are 3 Inch Brown Square Rubber Caster Cups. 100% MONEY BACK GUARANTEE - When you purchase this Decorative CasterMaster Caster Cups, you're offered a 100% money back guarantee within 60 days of your purchase. Test it out and try it out.