This guide rod is constructed from steel. It features a nylon constructed tip bushing and a spring-loaded design for self-adjustment. It fits on Slimfold and other similar styled doors. Spring-loaded for self-adjustment and easy door removal. 1/4 in. outside diameter x 5-1/2 in. steel pin with 3/8 in. outside diameter nylon cap. Steel rod with plastic cap. Fits Slimfold brand doors. Easy to install with a few simple tools.