Package Contents: A set of 4 double shower door rollers (2 top and 2 bottom). Each wheel comes with anti-collision block + stainless steel screw. Galvanized door rollers: Upper and lower double shower door rollers (diameter) 23mm, electroplated surface, anti-rust; suitable for glass door thickness 4-6mm, glass opening 12.5-14mm. These replacement shower door wheels are suitable for most shower rooms, bathrooms showers and steam rooms, and are installed at the top and bottom of the shower door for easy opening and closing. There is no noise when opening the shower door. shower, and these glass shower door rollers help it slide smoothly. It is easy to install and maintain. Scope of delivery: 4 pieces