The placement of the resistance coils is carefully designed to provide uniform heat distribution. The refractory material is backed by layers of insulation to minimize back heat loss. The standard housing is made of heavy gauge aluminized steel. Optional housing materials include 304 Stainless Steel. The backside of the housing has a terminal box for electrical wiring with ceramic terminal bushings and stainless steel screw terminals. Options available include: Standard quartz tube thermowell and clamp on the short side, standard Type K or J 1/8" diameter thermocouple probes and various back mounted thermowell/thermocouple combinations.