TRI-ONIC® current-limiting time-delay fuses are engineered for overcurrent protection of motors and transformers, service entrance equipment, feeder and branch circuits. Time-delay for motor start-ups and transformer inrush currents without nuisance opening. Current-limiting for low peak let-thru current. Rejection-style design prevents replacement errors (when used with recommended fuse blocks). Easy-to-read label for quick brand recognition and replacement. Metal-embossed date and catalog number for traceability and lasting identification. Fiberglass body provides dimensional stability in harsh industrial settings. High-grade silica filler ensures fast arc quenching and high current limitation.