8 Piece Shower Door Rollers Single wheels, includes 4 upper rollers and 4 lower rollers. Good for replacement shower door rollers. Wheel diameter is 23mm, wheel width is 6mm. Minimum glass mounting hole is 11mm, 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 screws and plastic cover. These single shower door rollers fit glass shower doors. The sliding door roller kit makes the door sliding and effort saving. A practical hardware for the sliding glass shower door. The bath runner is easy to move and install. It can also move the door to save your space.