White aluminum quick rail to use as sliding door frames on your pull barn. Quick Rails hold to there name they are a time saver and they look really good to. Cut your 2x4s or 2x6s to the width you want the door minus a 1/4″. Slide them in and secure them to the quick rails there your sliding doors almost ready to be hung on your pull barn. Install the trolleys and then hang your new sliding door on your pull barn, once it is hung it is ready for the metal siding.