These bi-fold door guide caps are constructed of plastic and come 25 per pack. These replacement caps slide onto the tops of bi-fold guide rods to allow for smooth operation of doors. Use these caps to replace any worn or missing caps of matching dimensions to repair any poor, or rough-operating bi-fold doors. These caps are easy to install and used by many.Used to replace damaged or missing bi-fold door guide caps1/4 in. inside diameter, 3/8 in. outside cap diameter, 1/2 in. outside rim diameterUsed on 1/4 in. Dia steel pins, as on N-6730Plastic constructionItem does not require fasteners for installationFor further dimensional information, please see the line drawing