The Murata PRF18BA471QB5RB is a Positive Temperature Coefficient (PTC) thermistor with a 470 Ohm resistance at 50% power and is rated for use with up to 32V of electricity. It is medium-size, radial-leaded part manufactured specifically as an over-temperature shutoff, so it is particularly useful for circuit protection. It works by sensing an increase in its own temperature, at which point its internal resistance increases sharply, thus limiting the increased current flowing through the circuit. This protective effect helps to minimize damage and heat buildup, making it a highly reliable component for a range of applications.