US3J1 is a 1-pole 30A Class J UltraSafe modular fuse holder designed for 600V AC/DC applications. It accommodates 30A Class J or 22 x 58 mm French Ferrule fuses and qualifies as "finger-safe" to an IP20 grade of protection under IEC standards. The holder features a tough polyamide body, snap-mount capability to 35 mm DIN-rail, and provisions for locking in the open position during fuse changeouts or equipment servicing. It is suitable for use in 600 volt motors, transformers, lighting, heating, control circuits, and general loads. The unit is UL Listed, CSA Certified, and IEC certified, with a short-circuit current rating (SCCR) of 200kA, providing reliable protection and ease of installation in industrial and commercial electrical systems.