The M-D Adjustable Aluminum & Re-enforced Composite Threshold features an adjustable riser to seal uneven gaps underneath your door. Manufactured with a thermal break design, this threshold is ideal for extreme temperature climates. The thermal break material is positioned on the interior part of the doorway, creating a thermally insulated barrier. This barrier prevents the temperatures from outside the home from being transferred through the threshold into the home. This reduces heat and frost from building up on the threshold. This product protects the home against drafts, moisture, dust and insects. The threshold can be used to install with a new door or to replace an existing threshold. All of the hardware needed for installation is included. Before installation, the threshold can be cut to a desired length by using a hacksaw. To best seal your doorway, this product can be used with an door sweep or an under door seal.