[Quantity]: 8 shower enclosure casters, consisting of 4 upper casters and 4 lower casters. Good for replacement shower door rollers. [Size]: Shower door rollers is 23mm, the maximum glass thickness is 6mm. suitable for glass doors with a thickness of approximately 5-6 mm. [Material]: Shower door rollers are made of ABS. It is rustless, sturdy and durable, stable in quality and has a long service life. [Easy Installation]: Shower door rollers is easy to move and install. Individual shower door rollers fit glass shower doors. A handy piece of hardware for the sliding glass door. [Application]: Shower cabin casters for shower cabins and massage cabins, bathrooms, jacuzzi and even for furniture. That doors and sliding systems can be opened easily and smoothly using our rollers