A Limitron JKS-400 fuse is a type of electrical fuse used to protect electrical circuits and equipment from damage caused by overcurrents. It is rated for 400 amps and is designed for use in industrial and commercial applications. The fuse features a high interrupting rating and is made with a ceramic body for added durability. The Limitron JKS-400 fuse is typically used in electrical panels, switchgear, and other electrical equipment where overcurrent protection is needed.