Package Content You will receive 4 bathtub rollers, roller diameter: 23 mm; comes with screws, screw size: M4*12mm, enough quantity can meet your needs. Materials Made of nylon roller and copper mandrel, has good overall performance. If you encounter problems when sliding the shower door, you can use it to repair it to ensure the most comfortable sliding of your door. Shower Door Wheel Roller High durability and long service life. The design is reasonable, make the shower roller effortless to use and reasonably implement the glass quality assigned to them, to control the movement in a given direction. Easy to Use Easy to install. It has good stability, low friction coefficient and good mute effect. It is often used in the sliding rails of bathroom sliding glass doors. ApplicationsThe shower door sliding rail is suitable for most shower rooms, shower stalls, bathtubs and steam rooms, etc. The sliding rail allows you to slide the bathroom door easily and smoothly when you use it. Suitable for most shower stalls, shower enclosures and steam rooms. Specifications: Material: Nylon roller + copper mandrel Roller Outer Diameter: 23 mm Screw Size: M4*12mm Package Includes: 4 x Shower Door Rollers 4 x M4 Screws Note: Please measure the dimensions for better installation before purchase. We only provide one size screw, if you need a different size screw, you need to buy it yourself.