Time delay. 125VAC only. Momentary overloads won't blow fuse. Designed to fit matching adapters. Type-S/SL Fuses are designed only to screw into adapters of the same amperage in the fuse holders. This prevents mismatching and the possibility of over-fusing a circuit. The Time Delay Feature of this product prevents temporary power surges from blowing the fuse unnecessarily, as a result of momentary current overloads when appliance motors startup. Fuse Selection Chart: Type: S & SL; Base: Unique base size for each amperage; Features: Varying base sizes prevent use of wrong amperage. Requires adapters installed in fuse box. Time delay prevents fuses from blowing unnecessarily when momentary voltage spikes occur. This Jasco product comes with a 90-day limited warranty. Visit www.byjasco.com for warranty details. Questions? Contact us at 1-800-654-8483 between 7:30 am - 5:00 pm CST. UL listed. Made in Mexico.