Same size as ordinary fuses. 10 secs minimum time lag at 500% rated current prevents shutdowns caused by starting currents or other harmless overloads. Guards motor against burnout from overloads or single phasing. Operates cooler than other fuse types, reduces heating in switches and panels. 13/16 in Dia x 5 in L. Class RK5, 600 V maximum. UL Listed, CSA Certified.