11 Electric heating systems for roofs, namely, cables, electric mats, roofing and wall panels, eaves, sensors, switches, controllers, thermostats and accessories therewith for roof heating systems, sold as a unit; hydronically-heated roof covering systems comprised primarily of roofing and wall panels, eaves, tubes, pipes and manifolds, sensors, switches, controllers, thermostats and accessories therewith, sold as a unit; electrically or hydronically heated roof coverings