Watt-Flex(tm) split-sheath cartridge heaters last longer, provide more even and responsive heat and eliminate bore seizure, reducing machine downtime and reducing the cost of process heating. The continuous heating coil eliminates sectional burnout, typical of conventional heaters. It also allows for a hot tip for application of focused heat. When energized, the split-sheath expands to contact the bore and provide more effective heat transfer. And, when de-energized, it will contract for warranted removal … if it gets stuck in a properly sized bore, we’ll replace it free of charge. REDUCE YOUR COST OF PROCESS HEATING.