Wheel Thickness: 6mm. Material: ABS plastic electroplating + ABS electroplating + zinc alloy bracket. Replace the shower door wheels - diameter 25mm. Available for glass doors with 12mm holes. Description: Replacement shower door rollers - smooth gliding. Suitable for most shower and sauna doors. They are designed for 4 to 8 mm thick glass. Contents: 8 Shower Door Rollers - We specialize in heavy duty shower door rollers.