8 Piece Shower Door Rollers Single Wheels, includes 4 top rollers and 4 bottom rollers. Good for replacement shower door rollers. Wheel diameter is 23mm, wheel width is 6mm. The minimum glass mounting hole is 11mm, the maximum glass thickness is 6mm. The distance between the center of the mounting hole and the edge of the glass is 18mm. The shower door roller is made of brass rod and ABS plastic material, it is rust resistant, sturdy and durable. Comes with screw and plastic cover. These single shower door rollers fit glass shower doors.The sliding door rollers kit makes the door sliding and saving effort. Convenient hardware for the sliding glass shower door. The bath path is easy to move and install. It can also move the door to save your space.