Type: 4 Piece Shower Door Roller Wheel Thickness: 5.5mm, comes with screws, suitable for 4-6mm thick shower door. Roller Diameter: 20mm, inner hole: 5mm, fixed with M4 screw. High Quality: The pulley is made of copper + POM wheel, and the screw is made of stainless steel, corrosion and rust resistant, with good overall performance. Bearing Component: Pulley has high load capacity and good stability; low coefficient of friction, provides smooth and quiet operation. Application: Suitable for shower doors, massage cabins, bathtubs, whirlpools, and furniture fittings. Ensures doors open easily and smoothly. Ideal replacement for damaged or worn shower door rollers. Easy Installation: Commonly used for bathroom sliding glass door pulleys and tracks. Measurement (before ordering): Wheel thickness: 5.5mm, suitable for 4-6mm thick shower doors. Roller diameter: 20mm, inner hole: 5mm, fixed with M4 screw. Package Contents: 4pcs Shower Door Rollers, 4pcs M4 Stainless Steel Screws. Suitable for bathroom doors. Shower door rollers fit most shower enclosures, including steam rooms. Installed at the top and bottom of the door for smooth operation. Packaged quantity: 4 pieces. Product color: white.