The OHMITE RHL250E is a wirewound rheostat, a type of variable resistor used for controlling electrical power. These rheostats are characterized by their robust construction and ability to handle significant power dissipation. They find applications in industrial equipment, motor speed control, and laboratory instrumentation. The datasheet indicates a finite life due to mechanical wear, and models H, J, K, L, and N are listed under UL and CSA standards. All rheostats have a 10% tolerance.