The OHMITE RHS15R is a wirewound rheostat, a type of variable resistor commonly used in industrial applications for controlling voltage or current. These rheostats are electro-mechanical devices, subject to mechanical wear and therefore have a finite life. They are available in various configurations with different wattage ratings, core types, and shaft rotation options to suit diverse application needs. Models H, J, K, L, and N are listed under UL File No. E-10946 and CSA File No. 21309.