Material: Made of POM, which combines high stiffness and strength with exceptional resilience, favorable sliding friction properties, and excellent dimensional stability. Resistant to fuels and other fluids, as well as high temperatures. Features brass shower door rollers and stainless steel screws for corrosion resistance, durability, and long service life. Dimension: Roller diameter: 20mm (0.78in); inner hole: 5mm (0.19in); wheel thickness: 5.5mm (0.21in); screw length: 12mm (0.47in). Bearing Component: Ensures smooth door operation with slight forward or backward movement. Provides effortless rolling for shower cabins and hydromassage enclosures, effectively supporting the weight of glass doors and controlling movement in the intended direction, enhancing durability and lifespan. Waterproof: Utilizes special ultra-sealing grease with PTFE content to significantly extend wheel life. Prevents water ingress, protects against corrosion, and forms a long-lasting water-repellent protective layer to support mechanism longevity. Uses: Ideal for shower door rollers, massage shower stalls, bathtubs, hot tubs, and furniture trim. Facilitates easy opening and closing of shower doors. Color: As shown Quantity: 4 pieces