This cable consists of solid bare copper conductors with PVC insulation & a tubed polypropylene jacket over the untwisted, insulated conductors. Copper Conductors, Polyproplyene Insulation, Polyvinyl-Chloride (PVC) Jacket Construction. Wiring of thermostat controls, heating and air conditioning equipment, doorbells, as well as other low voltage applications. Sunlight-resistant (except plenum). Sequential Footage Markings on spools.