Littelfuse SM20 Series surface mount varistors are designed for use in applications requiring high-energy / transient current capability. The SM20 Series includes AC rated parts designed to operate continuously across AC power lines. The DC rated parts are suitable for automotive applications. This Littelfuse series comprises a Nylon molded package with folded tin plated metal leads for soldering to board. Littelfuse SM20 Series surface mount varistors are based on a radial 20mm internal varistor element with similar characteristics to the Littelfuse LA / ZA series of varistors. SM20 Series devices feature a DC Voltage Rating of 26VDC and an AC Voltage Rating of 175 - 320AC as well as no de-rating up to 85ºC ambient.