Package Content: Set of 4 double shower door rollers (2pcs top and 2pcs bottom). (recommended for 14mm glass hole) Galvanized Door Rollers: Shower door double rollers top and bottom 23mm (diameter), plated surface, rust-proof; Suitable for glass door thickness 4-6mm, open glass hole 13.5-14mm. These replacement shower door wheels are suitable for most shower enclosures, shower stalls and steam rooms, installed on the top and bottom of the shower door for easy opening and closing (recommended for 14mm glass hole) No noise when opening the shower door and these glass shower door rollers ensure smooth sliding. It is easy to install and maintain. (recommended for 14mm glass hole)