Shower Door Wheels, Lance Home 8Pcs Double Twin Top / Bottom Shower Door Rollers / Runners / Pulleys / Wheels Bathroom Replacement Parts 25mm Diameter 1. Package includes: 4 upper rollers and 4 bottom rollers, in total 8pcs 2. These single shower door rollers fit glass shower doors where the distance from the center of the hole to edge of glass is 18mm. 3. Diameter of the wheel: 25mm; Width of the wheel: 5mm. Minimum Hole size in the glass: 11mm. Suitable for 3-6 mm glass thickness. 4. Material: Plastic, Nylon, A Plastic, Nylon BS and stainless steel. 5. Comes with screw cover caps. Spring loaded action can also fit curved showers. Designed with a nut and a plastic cover.