Specifications: Material: Plastic, Nylon, A Plastic, Nylon BS and stainless steel Color: Grey+White Diameter of the wheel: 25mm/0.98" Width of the wheel: 6mm/0.24" Minimum Hole size in the glass: 11mm/0.43" Maximum glass thickness: 6mm/0.24" Comes with screw cover caps. Spring loaded action can also fit curved showers. Designed with a nut and a plastic cover Quantity: 8 Pcs/1 Set Note: Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! No Retail Package Package Contents: 8 x Single Shower Door Rollers (4 upper rollers and 4 bottom rollers)