... Outer diameter:2.0-5.5mm Heating conductor:Carbon Fiber, Product life:>3000 hours Bending test passed:5000times ... classrooms, swimming pools, stadiums and amusement parks for kids, also for greenhouses and artificial incubation rooms. Outdoor application: ... snow-melting for airport runway, roofs, gutters, heat preservation for pipelines, defrosting for drains, lands,stairways, ...