[Package Content] You will receive 4 bathtub rollers, roller diameter: 23mm; comes with screws, screw size: M4*12mm, enough quantity can meet your needs. [High-Quality Materials] Made of nylon roulette and copper mandrel, has good comprehensive 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, so that the shower rollers are effortless to use, and the quality of the glass assigned to them is reasonably executed to control the movement in a given direction. [Easy to Use] Installation is simple, and it can be used with the M4 screws provided. It has good stability, low friction coefficient and good mute effect. It is often used in sliding rails of bathroom glass sliding doors. [Applications] Shower door slide rail is suitable for most shower rooms, shower massage cabins, bathtubs and steam room