Cooper Bussman FRN-R-40 - Edison Replacement Time Delay Fuse - 40 Amp 250V - RK5 Dual Element Recommended for AC power distribution system mains,feeders, and branch circuits. True dual-element construction allows sizing of 125% FLA for motor backup protection. Superior overload and cycling capabilities. Dimensions: 3" length x 13/16" diameter Agency Approvals: UL Listed, Class RK5, Guide JDDZ, File E162363; CSA Certified, C22.2, No. 248.12, Class 1422-02, File 700489