Nylon and copper - Good elasticity, good wear resistance Cost-effective - Set of 8 casters, multiple replacements, spare parts in one order Dimensions - Wheel diameter - 27 mm. A perfect replacement - Over time, the casters need to be replaced. Only an additional screwdriver is needed for repair. Suitable for - For glass door openings: 10-12 mm; 12 mm recommended. Thickness: 4-6 mm. For shower doors and massage cabins, bathtubs, whirlpools, or other furniture. LESOLEIL Replacement Shower Door Rollers 23mm Shower Door Rollers, 8 Pack, 23mm Shower Roller Replace a defective bearing. Shower door track guides come with screw covers. Spring mechanism, also compatible with curved doors. With screws and plastic covers. Individual Shower Door Rollers/Gliders/Wheels/Pulleys Replacement Shower Door Roller, Fits Most Shower Enclosures. Fits most shower enclosures, shower stalls, and steam shower cabins. Easy to install. A solid and perfectly constructed item, ideal for replacing defective shower