Shower door plastic track dimensions: The sliding shower door plastic track measures 3 inches in length, with a wall height of 9/16 inches and a track slot width of 1/2 inch. This track is compatible with glass up to 7/16 inches thick, and its suitable dimensions will not take up too much time or space. MATERIAL: White plastic construction, made of high quality material, not easy to be damaged and long service life. EASY TO INSTALL: Shower Door Track Guide. This glass shower door lower rail assembly keeps the shower door fully aligned; no special tools or skills required. Made of extruded metal frame, the sliding shower door tub enclosure is very easy to install together. GOOD FRICTION AND WEAR CHARACTERISTICS: This sliding shower door lower rail plastic has low static and dynamic coefficients of friction, and the material is abrasion resistant. This helps to extend the life of the rail. EASY TO USE: this is the best alternative to glass shower door rail assemblies. It is easy to install, dampens vibrations and has good sound deadening. It is also quieter in operation, making it ideal for showering in a quiet environment.