3M Windo-Weld Round Ribbon Sealer is designed as one roll of sealer with setting blocks. We constructed this ribbon sealer with a unique feature of controlled compressability which allows for easy installation. This product will not squeeze out or allow light to contact pinchweld. This roll of sealer comes with a sufficient amount of material to replace one windshield or backlite. Material: Rubber, Adhesive Type: Butyl Rubber