The DS1 oil-based duct seal compound fills irregular openings to protect from air, dust or water while providing vibration dampening properties. The non-hardening sealant adheres to metal, masonry, wood and plastic. Duct seal is non-corrosive, non-toxic, contains no asbestos and will not stain or harm the user fts hands. Safe and easy to use with no unpleasant odor. Maximum temperature rating of 210 deg F (99 deg C). Dielectric Strength 200 (V/Mil). Color Green. 1 lb package.