GREAT STUFF PRO Window & Door Closed-cell, Insulating Foam Sealant creates an air tight seal by expanding between window and door frame and the rough opening. The special low expansion formula does not distort or bow window and door frames when applied properly. Great Stuff helps seal out moisture and air to help minimize conditioned or heated air loss resulting in a more energy efficient home. Great Stuff window and door PRO cans are used with foam gun applicators. These cans are different from the retail cans which have plastic straws attached.