Advanced EK Series Seals are the ultimate the ultimate slide-out seal systems. Can be used for new installations or when upgrading worn out rubber seals. Order in two parts: The EK Base purchased separately, comes with wiper and is designed with straight edge for easy alignment with adhesive backing; Fasteners may be used to install as well. The "D" Seal,easily slides on to track in base, hides fasteners, and provides a positive seal. EK Series may also be used on interior wall for protection when slide-out room is extended or when replacing a double seal. EK D Seal comes in 35' Roll. Purchase separately,Keller# 5918384 EK Seal Base.