23mm Shower Door Rollers for Curved Doors, Shower Roller Wheels Replacement Shower Door Wheels Parts Spares for Glass Sliding Doors Specifications: These curved shower door rollers have a 23mm diameter, ideal for glass doors with a thickness of 4-6mm. Both the top and bottom rollers fit glass apertures ranging from 12-14mm. The top roller’s height can be adjusted by up to 8mm using stainless steel screws, while the bottom roller’s spring height automatically adapts based on the top roller’s position. .