Type S/SL fuses are designed for use in circuits found in motorized appliances and equipment such as washers, dryers, furnaces or air conditioners. The time delay feature of this fuse prevents temporary power surges from blowing the fuse. Type-S/SL Fuses are engineered only to screw into adapters of the same Amperage in the fuse holders. This prevents mismatching and the possibility of over-fusing a circuit Installation instruction included UL Listed 125 Vac time-delay rejection base helps prevent overfusing.