Nylon and copper - good elasticity, good wear resistance Economical - set of 4 rollers, multiple changes, Measurements - wheel diameter - 27mm. Perfect replacement - Rollers need to be replaced over time. Just use an extra screwdriver to fix Suitable for - Glass door opening: 10 ~ 12 mm; 12 mm is recommended. Thickness: 4-6 mm. Shower and massage cabins, bathtubs, jacuzzi or any other furniture Note: The data are all manually measured, please allow 1-3 cm error, due to the difference in light and display, there will be a certain color difference, the actual object received shall prevail.