C.R. LAURENCE A4263 CRL Black 3/64" Sealstrip Glass Setting Tape. CRL Sealstrip holds glass firmly and permanently, and also seals against dirt, moisture, and weather. Sealstrip Glass Setting Tape insulates against sound and vibration, and won"t stretch out of shape. It"s thin enough so it doesn"t crowd the glass and cause cracking or breaking. Just fold it over the glass edge, insert glass in the metal frame or channel, and trim with a knife or razor blade. Technical Specifications: Specific Gravity - 1.24; Tensile Strength - 275; Elongation % - 100; Durometer - 60. Part Numbers Variations: A4263