Sealing putty is a butyl rubber compound used for a wide variety of applications in the HVAC industry. This product is multipurpose being used to seal around extension wings, extension air ducts, and adaptors on window air conditioners. Other uses include sealing around tube entries, over screw heads, under hinges plates, and at breaker strips. This product, being water-resistant and permanently pliable, makes it long-lasting and able to withstand the elements for a more efficient seal. This product is available in slugs, rolls, or rope form.