CRL RTV408 Industrial and Construction Silicone is a neutral cure, medium modulus, 100% Silicone Sealant that cures to a tough, flexible rubber when exposed to moisture. RTV408 features primerless adhesion to: aluminum, stainless steel, most plastics, rigid PVC (vinyl), phenolic resin, glass, ceramic, and most reflective-coated glasses. All surfaces must be properly cleaned and the sealant tooled for good adhesion. Cat. No. S1L2100 Primer may be required for these and other substrates as well. Review crlaurence.com/sealants-technical for our Sealant Guidelines to Good Glazing.