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

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

Q: Is it ok to use this tester for the 20a power outlet (not gfci)?

A Very good question, since the device name starts with GFCI. Answer is YES, because despite the name, the device is mainly a regular outlet tester, checking cross wiring, missing wiring, and reporting voltages, all worthwhile tests for non-GFCI outlet. Also works with 15amp & 30amp with adapter. Thanks for the question.

Q: Most of the outlets in the basement where i'm living say >6.00 when i test them. are they wired wrong? is it safe to use the outlets?

It is not safe to use those outlets. If an outlet is good, the green light on the tester should illuminate, and the display should register a voltage close to 120 volts.

Q: Is this accurate enough to measure with some confidence which is the most upstream receptacle in a circuit for choosing gfci location?

Resolution accuracy inadequate for that task. Displayed digits determines resolution. In this case, meter accuracy will not be and can not be better than +/- 1 volt because digital resolution is always +/- 1 in the least significant digit. Example: If measuring a true, standardised 120 volts, meter might display 119V (-1), 120V or 121V (+1) if calibrated/adjusted correctly. You've got the right idea, but this meter displays only 2-1/2 digits (120V). You will need a meter with 3-1/2 (120.0V) digits displayed. Worst case resolution at 120 volts will then be ~0.1V (100 mV). You need to see those millivolts differences. Get one with stated accuracy and preferably calibrated. Cheers!

Q: What will happen if you press the gfci test on a non gfci? will it do nothing. or will it trip the breaker in the panel, and i have to flip the switch

The amber lights on the tester will blink, nothing will trip.

4.8/5

Product ID: 557085750

Secure Transaction

Details

Brand
KLEIN TOOLS
Power Source
Corded
Style
Receptacle
Colour
Green Red
Item Weight
0.26 Pounds

📊Clear LCD readout

⏱️GFCI trip time display

🛠️Detects wiring faults

Frequently Bought Together

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

Klein Tools 80016 Circuit Breaker Finder Tool Kit with Accessories, 2-Piece Set, Includes Cat. No. ET310 and Cat. No. 69411

Klein Tools NCVT3P Dual Range Non Contact Voltage Tester, 12 - 1000V AC Pen, Flashlight, Audible and Flashing LED Alarms, Pocket Clip

Description

⚡ Test smarter, work safer — the pro’s choice for flawless electrical checks!

VISUAL FAULT ALERTS - Bright green/red LEDs give you immediate, unmistakable wiring condition feedback.
HANDS FREE CONVENIENCE - Auto-Hold feature locks readings for those hard-to-reach outlets—work smarter, not harder.
PRECISION GFCI TESTING - Trip time display lets you troubleshoot with unmatched accuracy and speed.
INSTANT VOLTAGE CLARITY - Large backlit LCD ensures you never miss a detail, even in dim spaces.
NEXT LEVEL SAFETY DETECTION - Patent-pending tech spots open neutral and ground faults before they become hazards.

The Klein Tools RT250 is a professional-grade GFCI outlet tester designed for North American 120V 3-wire receptacles. Featuring a large backlit LCD, it provides clear voltage readings, identifies common wiring faults including open neutral and ground, and displays GFCI trip times for precise troubleshooting. With a CAT II 135V safety rating, auto-hold functionality, and bright LED indicators, it delivers reliable, efficient, and safe electrical testing trusted by professionals since 1857.

Specifications

Brand	KLEIN TOOLS
Power Source	Corded Electric
Style	Receptacle Tester
Colour	Green,Red
Item Weight	0.26 Pounds
Item dimensions L x W x H	11.5 x 2.9 x 5.1 Centimeters
Min. Operating Voltage	120 Volts
Specification Met	CSA
Measurement Type	Voltage Tester
Maximum Operating Voltage	120 Volts
UPC	092644693212
Manufacturer	Klein Tools
Global Trade Identification Number	00092644693212
Model number	RT250
Number of Memory Sticks	1
Special Feature	Large LCD Display; Patent Pending Detection of Open Neutral Open Ground Wiring Fault; Shows Amount of Time it Takes to Trip GFCI
Item Weight	118 g
Product Dimensions	11.51 x 2.95 x 5.08 cm; 117.93 g
Batteries	2 AAAA batteries required. (included)
Item model number	RT250
Item Height	2 Inches
Item Width	1.16 Inches
Included Components	2 x 1.5V AAA Alkaline Batteries and Manual
Are batteries included?	Yes

Have a Question? See What Others Asked

Is it ok to use this tester for the 20a power outlet (not gfci)?

Most of the outlets in the basement where i'm living say >6.00 when i test them. are they wired wrong? is it safe to use the outlets?

Is this accurate enough to measure with some confidence which is the most upstream receptacle in a circuit for choosing gfci location?

What will happen if you press the gfci test on a non gfci? will it do nothing. or will it trip the breaker in the panel, and i have to flip the switch

Common Questions

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Pooja R.

The customer service exceeded my expectations. Perfect for buying products you can't find elsewhere.

1 week ago

Meera L.

Smooth transaction and product arrived in perfect condition.

3 weeks ago

View all Trustpilot reviews

Shop Global, Save with Desertcart

Value for Money

Competitive prices on a vast range of products

Shop Globally

Serving millions of shoppers across more than 100 countries

Enhanced Protection

Trusted payment options loved by worldwide shoppers

Customer Assurance

Trusted payment options loved by worldwide shoppers.

Desertcart App

Shop on the go, anytime, anywhere.

€ 109.87

Duties & taxes incl.

Slovakiastore

Free Shipping

with PRO Membership

Free Returns

30 daysfor PRO membership users

15 dayswithout membership

Secure Transaction

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Imran F.

Very reliable shop with genuine products. Will definitely buy again!

2 weeks ago

Sneha T.

Received my product in pristine condition. Great service overall.

1 month ago

View all Trustpilot reviews