When driving a pickup truck equipped with a truck bed cover, a vacuum is created inside the pickup truck bed. This vacuum will pull debris into the pickup box through the truck bed tailgate gaps. The Retrax™ tailgate gasket will prevent dust, snow, water and exhaust fumes from being drawn in at the bottom and sides of the tailgate; the Retrax™ truck bed cover overlaps and seals the top of the tailgate. The Retrax™ tailgate gasket utilizes an outdoor 3M double-faced tape that is heat bonded to the rubber seals and is very easy to install. If your pickup has a topper, fiberglass lid, canvas cover or Retrax™ pickup bed cover, do yourself a favor and invest in a Retrax™ tailgate gasket.