Mersen UltraSafe™ modular 600 V fuse holders for Class J fuses introduce a new level of safety and ease for installing or replacing Class J fuses. UltraSafe™ holders qualify as finger-safe to an IP20 grade of protection under IEC standards. The US3J accommodates 30 A Class J or 22 x 58 mm French ferrule fuses. The US6J is for 60 A Class J fuses. UltraSafe™ holders are available in compact 1, 2, or 3-pole units, with or without blown fuse indicators in each pole. Multi-pole units can also be made up in the field by using the multiple-pole assembly kits. All units have provisions for locking in the open position for safety during fuse change outs or equipment servicing. US3J and US6J holders can be snap-mounted to 35 mm DIN rail and they have a unique latch which will stay open to allow re-positioning of the holder in the future. UltraSafe™ body material is tough and durable polyamide.