3M(TM) Scotch-Seal(TM) Duct Sealer 900 Gray, 1/10 gal cartridge, 12 per case An extremely smooth, easy handling knife or caulking grade sealant for sealing medium and high pressure heating and air conditioning ducts. Excellant for sealing Drive and S and large dimension spiral or rectangular duct joints. NOTE: Make-To-Order with a lead time of 60 days.