Material: Nylon copper, good elasticity, wear-resistant, corrosion-resistant, rust-preventative, stable quality, and long service life. Shower door rollers. Size: Wheel diameter: 27mm; wheel thickness: 5.5mm. Suitable for glass thickness: 4-6mm. Total length: approx. 33mm. For glass door openings: 10-12mm; 12mm recommended. DIY replacement: Easy and convenient to replace. Simply disassemble with a screwdriver and install new rollers on glass doors. Operates quietly and allows smooth sliding of the glass door. Easy to install and maintain. Designed to be installed at the top and bottom of shower doors for easy opening and closing. Wide application: Suitable for shower doors, massage cabins, bathtubs, Jacuzzi enclosures, and other furniture fittings. Compatible with most shower enclosures, shower cabins, and steam cabin enclosures. Package includes: Set of 8 rollers. Ideal spare or replacement set as rollers may require periodic replacement over time.