Littelfuse FLSR_ID Indicatorâ„¢ fuses provide visual blown fuse indication at a glance. The patented state-of-the-art solid state design provides maximum reliability and superior performance characteristics in a true dual-element design. The use of Indicator fuses reduces down-time, nuisance opening, increases safety and can save thousands of dollars in lost production time. Applications are service entrance switches, switchboard main and feeder switches, motor control center mains and motor branch circuits, individual fused combination motor controllers, distribution panelboards, industrial control panels, protection of fully-rated panelboards and loadcenters and all general purpose circuits.