The OHMITE RHS25RE is a wirewound rheostat, a type of variable resistor used to control electrical current. These rheostats are electro-mechanical devices, subject to mechanical wear and therefore have a finite life. They are commonly used in industrial applications where adjustable resistance is needed, such as motor speed control, lighting dimming, and volume adjustment. Consult factory for details regarding specific dimensions and performance characteristics. Models H, J, K, L and N are listed under UL File No. E-10946 and CSA File No. 21309.