RH Series 25W Wirewound Potentiometers. Ohmite RH Series wirewound potentiometers are designed and manufactured to operate smoothly and reliably over long periods of use. The RH Series has a ceramic body, high grade resistance alloy linear taper windings, vitreous enamel coating, metal spring contact arm, metal graphite composition and solder coated terminals. Typical applications for the RH series are motor speed controls, light dimmers and for equipment requiring convenient variable resistance settings. Features ; Benefits:. Tolerance ±10% 25 Watts