Klein Tools ET300 Digital Circuit Breaker Finder

No. The ET300 transmitter is built for 90 to 120V operation and plugs into a standard 120V outlet, so it traces 120V branch circuits only. It won't cover a 240V circuit. For a hardwired fixture or bare conductors, you'd need the 69411 accessory kit, which adds a light socket adapter and an alligator clip assembly so the transmitter can be fed from something other than a receptacle. That kit is sold separately.

Yes, and that's the point of it. The transmitter stays plugged into the 120V outlet while you carry the receiver to the panel, and the transmitter signal reaches up to 1000 feet. So a single tech can energize the circuit on one floor and read the panel on another without a second person or a radio. The receiver's flashing arrow indicator marks the breaker it picks out.

No. The ET300 works on a live 120V outlet, transmitting a signal down the energized branch circuit that the receiver reads at the panel. Identification is microprocessor controlled to cut down on false hits from adjacent breakers, and the finder locates the breaker for any standard 120V receptacle. That means you can map an occupied apartment or a tenant space without killing power at random to find out what feeds what.

Order Klein Tools ET300. You get the matched transmitter and receiver pair. The light socket adapter and alligator clip assembly are not included with the tool, they come in accessory kit Cat. No. 69411, ordered separately. If you're standardizing a maintenance fleet and expect to trace lighting circuits or panel-side connections, order the 69411 at the same time.

The ET300 answers one question: which breaker in the panel feeds this 120V outlet. It sends a signal from a plugged-in transmitter and the receiver flags the matching breaker at the panel with a flashing arrow. It is not a wall-scanning wire tracer for following a cable run through framing or finding a buried splice. If your job is identifying and labeling panel circuits in a building with no directory, this is the tool. If you're chasing a concealed run or an open conductor, look at a dedicated tone-and-probe wire tracer instead.

An auto power-off feature shuts the receiver down to preserve battery life, so a unit left on in a pouch or a van won't be dead the next morning. That matters on a tool that gets used occasionally rather than daily, which is how most property maintenance crews use a breaker finder.