specification1k,3k,6k,12k,24k, 36k, 48k Impedance range ... Outer diameter:2.0-5.5mm Heating conductor:Carbon Fiber, Product life:>3000 hours Bending test passed:5000times ... voltage. The radiation heating system supported by carbon fiber infrared calorific wires is widely used in: ... Indoor application: Carbon fiber infrared calorific wires laid under engineered flooring, ...