Constructed for de-icing residential roofs. Prevents ice dams from forming on cold roof overhangs. Provides path for water to flow along eaves trough, preventing ice and icicle build-up. Keeps down-spouts open and assures drainage. Plugs in a standard exterior plug. Includes: 1 cable with shingle clips and spacers. Option: RS-1, automatic control. 2-year warranty.