For all gutters, down spouts, heating and AC ducts and other seams in sheet metal surfaces. Cartridge has 3 in spout. Composed of SBR rubber and high quality resins, which cures to form a tough, rubbery seal that expands and contracts with the change of weather without cracking. Covers 31 ft at a 1/4 in bead and 14 ft at a 3/8 in bead.