1. Shower Door Plastic Guide Size: Sliding shower door plastic guide rail 3 inches long, 1-1/2 inches wide, a wall height of 9/16 inches, and a guide passage 1/2 inch wide, fits glass thicknesses of up to 7/16 in, the right size won't take up much of your time and space. 2. Easy To Install: Shower door track rail. This glass shower door lower rail assembly keeps the shower door properly aligned. No special tools or skills are required; the sliding shower door bathtub enclosure made of an extruded metal frame is very easy to install together. 3. Material: The glass shower door hardware is a white plastic structure made of high-quality material that is not easily damaged and has a long life. 4. Good Friction And Wear Characteristics: this sliding shower door bottom rail plastic has a low static and dynamic coefficient of friction, and the material is wear-resistant. This helps to extend the life of the guide.