Frost King Mortite F4 Caulking Cord, 45 ft L, Gray

Mortite is the original name in Do-It-Yourself fingertip caulking and it's still famous for its quality and versatility and ease of use. Sure, Mortite weatherstrip and caulking cord will seal windows effectively. But it's also widely used as a gasketing material, sound deadener insect barrier, crack filler and all-around plugger-upper.