The M-D Vinyl with Magnetic Strip Top and Sides Door Seal Kit for Steel Doors features a kerf design for channel fit doors to protect against drafts moisture dust and insects. Save on energy by sealing the top and sides of your door and keeping the heat or air conditioning from escaping. Made of premium vinyl this product stays flexible in cold temperatures. The kerf design is easy to install by simply pressing it into the channel of the door jamb. It is best used with steel doors because the magnetic strip creates a physical connection to the door creating a tight seal on the top and handle side. This kit comes with three pieces two 81 pieces for the vertical sides of the door frame and one 36 piece for the top of the door frame. Before installation cut to desired length using scissors.