The OHMITE RJS50R is a wirewound potentiometer, a type of variable resistor commonly used in industrial control systems, audio equipment, and other applications requiring precise resistance adjustments. These potentiometers are known for their durability and high power handling capabilities. They are subject to mechanical wear and have a finite life. Models H, J, G, K, L and N are listed under UL File No. E-10946 and CSA File No. 21309. All rheostats are 10% tolerance.