Klein Tools RT250 GFCI Outlet Tester with LCD Display, Electric Voltage Tester for Standard 3-Wire 120V Electrical Receptacles,Green/Red

Good price, arrived on time. A must for all electrical installers.

Buen producto, me llegó antes de la fecha programada, empaquetado y sellado. Usa 2 pilas AAA de 1.5 V. Ya viene con sus pilas. Se necesita un pequeño desarmador de cruz (la tapa usa un tornillo más pequeño de lo habitual) para insertar las pilas yo utilice uno del #1 y me funcionó perfectamente. Ya trae su instructivo en inglés español y francés.

I have one of those 3 LED testers already, the ones with the 2 yellow and one red light... and has a legend on it so that you can tell what is what. Works great... only issue is that when I was working outdoors or in a brightly lit room, it wasn't so obvious which LED were lit. So I bought the Klein as it wasn't a bad price and had the built in GFCI too. My old set, I had a separate GFCI tester which also worked great but just meant I had 2 separate testers. I played with the Klein soon as I got it having installed the batteries (Klein supplied I might add!!!!). You need to hold the power button down a couple of seconds and then the LCD comes alive. I tried it in various outlets around the house and found it to be a really effective device. The unit has only 2 LED's and there's no mistaking when they light up, both bright... A green one which clearly means OK and a red one meaning a fault in the wiring has been detected. I already had a purpose made miswired test lead I used for verifying the fault detection capability. Works great. I also like that it provides a reading of the actual voltage detected. It's not just a passive device. I have only one minor concern... When I put this in my toolbox I'm worried about something resting on the power switch and running the batteries down, so for now, having already carefully cut around the edge of the packaging, I'm keeping it in the packaged plastic. Might be overkill and maybe I'll buy a protective case for it if I feel inclined but for now, perfectly happy with the device and definitely recommend over the typical passive receptacle testers, even though they may be half the price.

Good product

As an electrician or serious DIY-er who cares about doing things right, this tester has quickly become one of my favorite go-to tools. The RT250 is packed with features and built to handle real-world job-site demands. What stands out: The large back-lit LCD display clearly shows voltage, wiring condition, and the time it takes a GFCI to trip—making testing thorough and faster. It automatically detects open neutral, open ground, and other common wiring faults—no more guesswork. The built-in GFCI test button trips the device and the timer measures how long it takes—great for verifying that the GFCI meets spec. Rugged build: rated for a 6.6-foot (2 m) drop and meets CAT II 135 V safety rating—solid for a busy job site. It’s compact and lightweight (just 4.8 oz) but feels tough—durable housing and robust plug make it practical for everyday use. My experience on the job: I’ve used this tester across new installs, upgrades, and troubleshooting older receptacles. It quickly flags incorrect wiring (open ground, reverse hot/neutral, etc.), and the extra info like voltage readout and trip time saves me from coming back later for retests. Switching between circuits is fast, the screen holds readings with Auto-Hold (perfect for hard-to-reach outlets), and the indicator LEDs still give quick visual cues when I want them. Final verdict: If you’re working with North American 3-wire 120 V outlets (especially ones with GFCI protection), this tester hits all the right notes: precision diagnostics, rugged build, and efficient troubleshooting. It’s built like a pro tool—and priced so that it’s worth having in your bag every day. I highly recommend it.