Purpose The Slipstick caster cup provides protection for hardwood, laminate, ceramic tile, parquet, and slate floors against scratches and prevents them from leaving unsightly indentions and marks on these surfaces. Design Featuring a rubberized, non-slip O-Ring on the bottom, the Slipstick Caster Cup is designed to protect floors and stop furniture on wheels from moving. The Slipstick also helps reduce or prevent unsightly dents left in floors by wheels. Size & Weight Capacities These Slipstick castor cups are designed for roller wheels up to 2-1/4" (56mm) in width, and each cup can support up to 500 lb. (This is the weight capacity of the cup itself - Your wheels and other items may not support this much weight.) These cups can be used under legs with a diameter 2-3/8" to 2-5/8".