Top quality chrome and zinc alloy replacement shower door roller set, 2 height adjustable upper and 2 spring loaded quick release lowers. Excellent quality uses marine grade 304 stainless steel so won't rust ! Suitable for many different makes with 8mm glass hole 18mm or less from the hole center to edge of glass. Wheel diameters 23.5mm x 6mm. Swivel action to also fit curved and quadrant showers with glass thickness 6mm. These are also available to fit 8mm glass send a message to request 8mm if that size is required.