The multi position (extraction) mantle has a built-in electronic controller. The vented case's unique air flow ensures the outer case remains safe to touch. Individual built-in solid state electronic controls enable easy regulation of heater while removing sparking associated with mechanical switching. Three 12.7 mm diameter support rods are included. Top cover is polypropylene and external surfaces are powder coated giving good general chemical resistance. Coiled heating element is suspended within a thermal insulating cartridge to provide maximum heat transfer and support. Earth (ground) screen encloses the heater for added safety. Individual heater cartridges are replaceable. Neon lights indicate when power is on and supplied to heaters and if applicable supplied to stirrers. Allow the solution to be stirred and heated simultaneously.<BR />Provide stirring speeds of between 50 to 1000 rpm. One stirring control operates each set of three recesses.