This EK seal has the ultimate slide out seal system. It can be used for new installations or when you are upgrading worn out rubber seals. The EK Seal base comes with wiper and is designed with straight edge for easy alignment with adhesive backing. Fasteners maybe used to install as well. The D seal is very helpful when it slides on because it hides fasteners and provides a positive seal. This kit may be used on an interior wall for protection when slide out room is extended or when placing a double seal.