CRL Foam Core Butyl Tape is required on quarter windows of various vehicles and back glass installations. It is also ideal for sealing joints in RVs, motor homes, trailers, and boats, places where joints are subject to the stress of movement and the effects of constant exposure to the elements. The soft inner core responds to body movement, expansion, and contraction. These versatile foam extrusions seal effectively against water penetration to prevent corrosion or moisture damage. Foam Core Butyl Tape controls sound better than standard butyl tape. 24 Rolls per Case.