WHAT IS IT: RoofMate Self-Regulating Heating Cable is specifically designed for residential roofing and gutters to prevent damage caused by ice formations, such as ice dams. It is direct-to-consumer Swiss manufactured with 100% quality control. This means we test every single cable made. Manufactured by GammaSwiss – 30 years of success in electric heating cables used in industry all over the world, now available to you for your home. RoofMate comes with a 5-year Warranty and is ETL Certified. Each cable measures 13x6mm, consists of durable PVC inner insulation and a continuous ground braid. This guarantees maximum safety and reliability. The illuminated plug helps to easily see when your cable is functioning. Each cable has 10-ft cold lead, plus the self-regulating length listed. INSTALLATION: RoofMate cables can be overlapped during installation and operation, won't overheat, and can be used on all roofing materials except wood. Please read the installation manual and follow all instructions. Using roof clips: Do not use nails, adhesives or sealants to attach clips to the cable. Clips are not included because the type of clip you'll use depends on the type of roof you have. Be sure to use clips specific to your type of roof, e.g metal, asphalt, rubber, etc. We recommend checking with your local hardware store, the internet or asking a professional installer what they suggest. HOW DOES IT WORK: 'Self-regulating' means the cable automatically adjusts its heat output according to the outside temperature: colder outside=hotter cable, less cold outside=less hot cable. This way the cable only uses as much energy as needed to melt snow and ice. If only a certain part of the cable is getting snowed on, then only that part will get warmer. The entire cable adjusts independently. No portion of it will get hotter than it needs to be.