Cooper Bussmann BP/FRN-R-50ID 250-volt Current Limiting Class RK5 Fuse with Fusetron Dual Element and Time Delay, 2 Pack Features Fusetron energy efficient fuses 23% more energy efficient Their dualelement feature allows closer sizing to load for superior protection of motors and transformers Help protect motors from burnout caused by overloads or single-phasing The time-delay feature allows the initial startup current surge for typical motors to pass Label Darkens If Fuse Has Opened Dual Element, Time Delay UL Listed, Carded USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.