In summary, Multifuse® components are often referred to as Polymer PTCs, resettable fuses, or thermistors. These devices are made from unique conductive polymer materials that exhibit a PTC effect. Under normal operating conditions in a circuit, the PPTC is in a low resistive state. In a fault current event the PPTC changes from low resistance to high resistance and limits the circuit current to a trickle current. It will remain at a high resistance until the fault is cleared and the power is cycled, it then resets and returns to the normal operating current. The MF-RM series is the most recent addition to the Multifuse® family, designed to operate in mains rated AC circuits of up to 240 VAC. The first models of this series provide hold current values from 50 mA to 550 mA. All models within the family are UL listed and come in a radial through-hole package.