Quality Materials: The shower door rollers are made of zinc alloy and ABS, ensuring strength, durability and long service life. Noise Reduction: The 4 double rollers (2 upper and 2 lower) effectively reduce the noise when closing the sliding shower door. Dimensions and Compatibility: Roller diameter: 23 mm; suitable for glass doors with a thickness of 4 to 6 mm, and most shower and massage enclosures. Easy Installation: Easily replace worn rollers without professional help. Versatility: Shower door rollers are suitable for various shower enclosures, shower enclosures, and massage enclosures with 4-6mm thick glass doors.