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⚡ Power up your safety game with precision testing!
The Klein Tools RT250 is a professional-grade GFCI outlet tester designed for North American 3-wire 120V receptacles. Featuring a large backlit LCD, it provides clear voltage readings, detects common wiring faults including open neutral and ground, and displays GFCI trip times for fast troubleshooting. With a CAT II 135V safety rating, auto-hold functionality, and bright LED indicators, it delivers reliable, easy-to-use electrical safety testing trusted by pros since 1857.


















| ASIN | B08QW7K1JJ |
| Best Sellers Rank | #1,503 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #3 in Voltage Testers |
| Brand | KLEIN TOOLS |
| Brand Name | KLEIN TOOLS |
| Color | Multi |
| Customer Reviews | 4.8 out of 5 stars 11,477 Reviews |
| Global Trade Identification Number | 00092644693212 |
| Included Components | 2 x 1.5V AAA Alkaline Batteries and Manual |
| Item Dimensions | 4.53 x 1.16 x 2 inches |
| Item Type Name | Klein Tools RT250 GFCI Receptacle Tester with LCD Display, for Standard 3-Wire 120V Electrical Outlets |
| Item Weight | 0.26 Pounds |
| Item dimensions L x W x H | 4.53 x 1.16 x 2 inches |
| Manufacturer | Klein Tools |
| Maximum Operating Voltage | 120 Volts |
| Measurement Type | Voltmeter |
| Minimum Operating Voltage | 120 Volts (AC) |
| Model | RT250 |
| Part Number | RT250 |
| Power Source | Corded Electric |
| Specification Met | CSA |
| Style | Receptacle Tester |
| Style Name | Receptacle Tester |
| UPC | 092644693212 |
| Unit Count | 1 Count |
| Upper Temperature Rating | 60 Degrees Celsius |
| Warranty Description | Please refer to attached warranty document for information |
‘**—
Excellent tool for testing electrical outlets
This tool makes testing electrical outlets quick and easy. It is especially helpful to locate GFI outlets that are chained together. The tester can purposely trip the GFI and you can locate the downstream outlets that do not have power. The only drawback is it can be difficult to remove it from some outlets.
L**M
Easy to read and use for proper outlet installation
An excellent product that takes the guess work out of electrical outlet installation. The display is easy to read and lets you know definitively if you are wired correctly or not. The red and green lights are nice as well as the LED voltage readout. Very accurate and a good value. Also great for checking GFI circuits.
J**N
RV Electrical Safety Tool – LCD Display Makes Testing Easy
RV Electrical Safety Tool – LCD Display Makes Testing Easy Used this Klein RT250 outlet tester in my RV to verify wiring at campsite pedestals and interior outlets—the LCD clearly shows voltage, wiring faults (open ground, reversed polarity), and GFCI trip time in seconds. The auto-hold feature lets me unplug and read results in tight spaces behind furniture. Only note: battery compartment could be more secure for rough travel, but after a year of regular use, it's proven reliable for catching wiring issues before plugging in sensitive electronics. Essential for RV electrical safety checks.
J**N
Essential Tool for Electricians and DIY Pros
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.
A**K
Decent product
Voltage reads 2V high. Other than that -- OK.
V**N
Never Trust an AC outlet till you measure first.
The essentials. Hot Neutral and ground for your 1800 watss of 120 VAC coming out of the wall. A most practical tool that in an instant lets you know the status of your outlet. When I don't have a Multimeter handy, this covers the tests perfectly. I work in a place that has questionable power from time to time. Something you should never be in doubt. This device helps you know your AC power is working correctly. An indispensable tool to keep you safe and aware of live outlets. A must have.
C**U
Easy to Use
Works great for our final checking after we did the electricity upgrade. The monitor is easy to read and accurately reflect the status of electricity wiring.
D**N
Simple and easy to use yet Amazing precision!!!
I picked up the Klein Tools RT250 GFCI Outlet Tester to help check a few outlets around my house, and I’m honestly impressed. This thing is super straightforward, just plug it in, the lights pop on, and you instantly know what’s going on with the wiring. No guesswork, no complicated setup, just clear results. The display is bright and easy to read, and the built-in GFCI test button is a lifesaver when checking bathroom and kitchen outlets. It helped me identify a miswired outlet in an older part of my house that I never would’ve caught otherwise. For something at this price, it feels durable and professional like something an electrician would actually use. If you’re a homeowner, DIYer, or just want peace of mind about the electrical safety in your place, this is a solid buy. Fast, accurate, and super easy to use. Highly recommend!
J**.
Excelente.
Excelente.
F**S
Handy Tool
This tester could save your life. Used in an RV with no issues - the tester showed all was well. Using the same tester in a house, it gave an indication of potential wiring issue, as the voltage showed 30VAC on first check and 123V on a subsequent check. It will also indicate ground issue, reverse polarity. Glad to have bought.
J**Z
Funcional
Funciona perfecto y es muy práctico lo volvería a comprar
M**A
Definitely recommend this tool.
Does exactly what the advertising says. Seems really well made from solid material.
E**J
Quality
Works perfectly, if only I could find we're I misplaced it.
Trustpilot
3 days ago
3 weeks ago