Littelfuse FLSR_Id Indicator™ 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.