The CRL Windshield Hold-Down Vacuum Cup Set is a complete system that firmly secures both the windshield and the molding during the adhesive curing process. Once you use the Vacuum Cups to position the glass you thread the Tie-Down Strap through the slits in the handles. Then the strap is pulled around the "A" Pillar on one side of the vehicle, and around the opposite "A" Pillar back to the surface of the windshield. From there it is threaded into the ratchet mechanism and tightened, holding both the glass and molding in place while the adhesive cures.