Multifuse® PPTC devices act as circuit protection components by limiting dangerous current surges, such as short circuits, from electrical equipment. They provide protection in this way as they react to an overcurrent event by changing from a very low resistive state to a very high resistive state. This is known as the positive temperature coefficient effect or PTC effect. What makes these devices special is that once the overcurrent surge has passed, the Multifuse® PPTC device will reset to its low resistive state and allow the equipment to resume operation. This is why they are commonly referred to as resettable fuses.