Cooper Bussmann S15 Type S Plug Fuse, 15 AmpTime delay, dual element S Series plug fuses provide a rejection feature (when used alone or with Fustat adapters to retrofit Edison base holders) to prevent overfusing of branch circuits. 4 pack 15 amps Non tamp Dual element, time delay plug fuse Plastic base with rejection threads. Use in typical application like residential load centers Applications benefiting from fuse rejection UL Listed.