Coil Heater Heating Element with Thermocouple is made of nickel chrome resistance wire placed inside chrome nickel steel tube that is filled with MgO powder.Spring coil heater is also known as high performance tubular heaters or cable heaters. Spring heater can be produced with or without built in thermocouples. Spring coil heater is widely used in heating engineering, mold, plastic industry, including the transfer machinery, medical equipment, casting process, welding, heat treatment process and many other industries and fields. http://www.etdzheater.com