0242.250UR is a highly integrated, miniature coordinated protection circuit component. It is not a simple fuse, but rather a device that physically and electrically integrates a precise Zener diode with a Polymer Positive Temperature Coefficient (PPTC) device within a single small surface-mount package.

Its core function is to provide robust overvoltage and overcurrent protection for sensitive DC power ports, particularly in low-voltage electronic equipment. It is primarily used to replace or enhance traditional "fuse + TVS diode" combination solutions.