A thermal miniature circuit breaker designed for plug-in installation in screw-type fuse terminal blocks UK 6-FSI/C and spring-cage fuse terminal blocks ST 4-FSI/C. It functions as an automatic protective device with a rated surge voltage of 2.5 kV. The breaker is rated for 250 V AC, 65 V DC, and 250 V AC (UL 1077 standards) and 72 V DC (UL 1077 standards). It has a rated current of 10 A, providing reliable overcurrent protection in electrical circuits.