Fouch 'N Foam Nowarp Window & Door Sealant Is Specially Formulated For Use Around Window And Door Frames. While It Can Be Used As An All-Purpose Foam, This Revolutionary Expanding Polyurethane Foam Is Designed To Seal And Insulate Without Exerting Pressure That Can Be Detrimental To Window Or Door Frame Stability. This Low Pressure Foam Is Actually Self-Venting Which Means That Once It Fills The Void, The Trapped Co2 Leaves The Product – Unlike Conventional Polyurethane Foam That May Continue To Expand And Apply Pressure. This Is Ideal For Sensitive Areas (Like Window And Door Frames Where The Gap Can Be Sealed Without Bowing The Frame - Even If The Area Is Overfilled With Foam.