Features: • 1-1/2 Wide By 10 Long Roll. • Rated To 225 Degrees Farenheit. • Pressure Sensitive Self Adhesive Backing. • Helps To Limit Air Leaking Between Your Insert And Masonry Fireplace Opening. Instructions: • Peel Off Backing And Apply To The Back Of The Fireplace Insert Flange To Seal The Space Between Flange And Masonry Surface.