Yosoo 2PCS Sliding Shower Doors 23mm Wheel Twin Double Bottom Zinc Alloy Shower Door Rollers/Runners/Wheels Materials: 304 stainless steel micro-bearing POM zinc alloy brass axis Diameter of wheels: 23mm Width of wheels: 6mm Minimum Hole size in the glass: 10mm Designed for use on 6mm glass doors Suitable for most shower enclosures, shower cabins and steam cabin enclosures