The Silicone 825 is a low modulus neutral curing silicone sealant based on a filled alkoxy curing system, it conforms to ISO11600 class: F 25LM when tested to ISO9047, Used for expansion joints to stone, brick, concrete & composite panels, perimeter pointing around all types of window & door frames. substrates: Glass, aluminum & PVC all are primer less, check out more sealants from Everbuild.