Combination set of the top pivot and guide wheel used by several bi-fold door manufacturers. Typically used on wood bi-fold doors, the top pivot is a nail on style with a 1/4 inch spring loaded pivot pin with a 3/8 inch base that fits into the pre-drilled hole. The 3/4 inch wide nylon pivot guide wheel is also a nail on style and has a 3/8 inch base that fits into the pre-drilled hole. Typically used on wood bi-fold doors.