NSI Intended for sealing around electrical service entries, junction boxes and other devices where weather-proofing is critical. Will stay soft and pliable for several years and has an excellent shelf life. Will not damage wire covers, glass, wood, painted surfaces, plastics or other materials it may contact. It is chemically inert, inhibiting no chemical activity and is nontoxic. Contains no asbestos or mineral fibers and no mineral oil which can shorten the effective life of the product. Remains pliable through a wide range of temperatures and will adhere to most clean dry surfaces.