Cartridge heaters are high efficiency heating elements. Diameters of cartridge heaters range from 0.25" to 1.25". Watt densities from 25 W/in2 to 200 W/in2 and sheath temperatures to 1800°F. Optional end seals resist contaminants and moisture from entering inside the heater. Chromalox provides a variety of sizes, wattage ratings, voltages and protective features to meet many challenging applications.