Amp-Trap low voltage time-delay fuse a 4 second minimum time-delay at 500% rating allows the A4BY to pass normal current surges and to coordinate with ground fault relays. Unique dimensions prevent replacement by other fuse classes. Blade stamped catalogue numbers for permanent identification. Glass melamine body and plated terminals provide superior reliability in harsh environments. Bolt-on mounting. Blade connection terminal type. Cylindrical rejection body style. GMG body material and silver-plated copper material contact. Applications: mains, feeders, circuit breakers, load centers, panel boards, switchboards, metering centers.