Provides Watertight Seals. Recommended for Aftermarket Sunroof Installations. CRL Sunroof Butyl Sealant Tape offers a watertight, gasket-like seal and is recommended for applications such as installing aftermarket sunroofs. The Butyl Sealant Tape offers outstanding resistance to weathering, and develops good adhesion to glass, metal, and most other surfaces. The tape is UV stable, non-permeable to gasses and moisture, and has a limited cold flow under load. One Roll will seal sunroofs up to 22" x 38". Flat Butyl Sealant Tape: 5/8" x 1/8"