Shower Door Roller Set of 8: Includes 4 upper rollers and 4 lower rollers, 8 in total; comes with screws and a plastic cover. Suitable for glass shower doors, shower enclosure doors, massage cabin doors, or sliding furniture accessories. Shower Roller Material: Made of brass and ABS plastic, sturdy and durable. Dimensions: The wheel size is approximately 23 mm in diameter, 6 mm in width; the maximum glass thickness is 6 mm; the distance from the center of the mounting hole to the edge of the glass is approximately 6 mm. Easy to Slide: The bathroom slider is easy to move and install, keeps the door balanced and allows the door to slide with minimal effort.