The Klein Tools RT250 is a GFCI receptacle tester with a backlit LCD display for use with North American 120V three-wire electrical outlets. It identifies common wiring faults, tests GFCI devices, and displays the trip time in milliseconds — providing more diagnostic detail than basic LED-only testers. Patent-pending simultaneous open neutral and open ground detection adds depth beyond standard fault identification. Rated CAT II 135V with 6.6-foot drop protection. Runs on two AAA batteries. Backed by Klein Tools' 1-year limited warranty.
What's the advantage of the LCD over LED-only outlet testers?
The RT250 displays the fault condition as readable text on screen. LED-only testers require you to match light patterns against a printed legend — the LCD eliminates that step and is easier to read under poor lighting.
Does the RT250 require batteries?
Yes — 2 AAA batteries power the LCD display. Unlike the RT210 and RT200, which draw power from the outlet, the RT250 needs working batteries to operate.
Can it test AFCI protection?
No — GFCI testing only. For AFCI testing, use the RT310, which generates an actual arc to trip AFCI devices.
Does the RT250 detect dual-open faults?
No — detecting simultaneous open neutral and open ground requires the RT310, which has dedicated dual-open fault detection logic.
What outlets does it work with?
Standard 3-wire grounded 120V North American receptacles. It does not support 240V, two-prong ungrounded, or international outlets.
What's the difference between the RT250 and RT310?
RT310 adds AFCI testing, a flexible 10-inch cord, dual-open fault detection, and a higher CAT III 135V rating. RT250 is GFCI-only with a cleaner LCD interface but no AFCI capability.
# Klein Tools® RT250 GFCI Receptacle Tester with LCD **Model:** `RT250` **Brand:** Klein Tools **Category:** Voltage Tester > The Klein Tools RT250 is a GFCI receptacle tester with a backlit LCD display for use with North American 120V three-wire electrical outlets. It identifies common wiring faults, tests GFCI devices, and displays the trip time in milliseconds — providing more diagnostic detail than basic LED-only testers. Patent-pending simultaneous open neutral and open ground detection adds depth beyond standard fault identification. Rated CAT II 135V with 6.6-foot drop protection. Runs on two AAA batteries. Backed by Klein Tools' 1-year limited warranty. ## Specifications | Attribute | Value | |---|---| | Product Type | GFCI Receptacle Tester with LCD | | Voltage Range Ac | 135V AC | | Cat Rating | CAT II 135V | | Tests Gfci | Yes | | Tests Afci | No | | Outlet Types Tested | 3-wire 120V standard receptacle | | Display Type | LCD | | Battery Type | 2 × AAA | | Battery Required | Yes | | Drop Protection Ft | 6.6 | | Overall Length In | 4.5 | | Assembled Weight Oz | 4.8 | | Barcode (UPC) | 092644693212 | | Warranty | 1-year limited | ## What's Included - Tester unit - 2 × 1.5V AAA alkaline batteries Source: https://www.jaspecs.com/klein-tools/voltage-tester/rt250-klein-tools-gfci-receptacle-tester-lcd/