The Electromantle Extraction Heaters offer a choice of three or six recesses. Individual built-in solid-state electronic controls enable easy regulation of each heater, while removing sparking associated with mechanical switching. Units include three 0.5"(12.7mm) diameter support rods. External surfaces are PTFE-coated and resistant to most chemical solutions. The robust construction permits continuous operation of the units as required by routine extraction tests. Element temperature range to 450°C.