The Ohmite RHL250 is a wirewound rheostat, a type of variable resistor commonly used in industrial applications for controlling voltage or current. These rheostats are known for their durability and precision, making them suitable for applications where accurate resistance adjustment is critical. They are subject to mechanical wear and have a finite life. Models H, J, K, L and N are listed under UL File No. E-10946 and CSA File No. 21309. All rheostats are 10% tolerance.