The RF3174-000 Resettable Fuses (PPTC) 240V .75A-HD 18A-MAX (R) is a positive temperature coefficient (PTC) device designed and manufactured by Littelfuse. It is a surge protector that acts as an automatic switch that will disconnect the supply voltage to the load if it experiences too much current. The fuse is capable of handling a 6mm diameter HD (.75A) of power and a maximum voltage of 240V, while being able to reset itself after the power has been removed for a predetermined period. The fuse features a highly reliable and stable diode designed to provide superior circuit protection in a wide variety of applications, including: power supplies, LED lighting, motor controls, and more. The RF3174-000 is part of the Radial PTC (R) series, which can be used in a wide variety of applications, and offers excellent current protection, as well as allowing users to reset the fuse quickly and easily.