The M-D Vinyl Concealed Kerf/Channel Fit Under Door Seal features vinyl fins for protection from drafts, moisture, dust and insects. Save on energy by sealing the bottom of the door and keeping the heat or air conditioning from escaping. This product requires a kerf channel on the bottom of the door. It is less visible than most Under Door Seals and is ideal for a more concealed look. Used to replace Under Door Seals on pre-hung doors and requires removal of the door to install in to the kerf channel at the bottom of the door. Before installation, cut to desired length using a hacksaw.