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Compact yellow plastic outlet tester with three indicator lights and North American plug prongs

Klein Tools RT210 GFCI Outlet Tester electrical system tool

SKU CH-B3CJ-CAGRD

Tests standard and GFCI outlets for common wiring faults and confirms ground-fault protection operation

  • FeaturesGFCI Outlet Tester, Cat Ii 300v, Hand Powered, false
  • Height5.3 L x 3.8 W x 1.5 H inches
  • Width5.3 L x 3.8 W x 1.5 H inches
  • Length5.3 L x 3.8 W x 1.5 H inches
  • Weight1.9 ounces
  • Sports Team1 Piece
  • Detects common wiring faults in standard and GFCI outlets
  • Confirms GFCI ground-fault device trips correctly for safety
  • Survives a 6.6-foot drop for jobsite durability
  • Operates from 32 to 140 °F across work environments
  • Tests 110/125 V AC 50/60 Hz three-wire receptacles

Klein Tools RT210 GFCI Outlet Tester

The Klein Tools RT210 tests standard and GFCI North American 110/125V AC receptacles. It identifies common wiring faults such as open ground, reverse polarity, open hot, open neutral and hot/ground reversed. Electricians, inspectors and homeowners use it to verify outlet safety before connecting equipment.

Plug-in operation with drop-rated durability

Insert the tester directly into a three-wire outlet; the indicator lights display the wiring condition using the chart on the housing. No batteries or external power are required. The unit withstands a 6.6-foot drop and operates from 32 to 140 degrees Fahrenheit, so it survives typical job-site handling.

Limited to 125 V AC CAT II 300 V environments

The tester works only on 50/60 Hz circuits up to 125 V AC and is rated CAT II 300 V. It cannot evaluate higher-voltage, three-phase or DC systems. It confirms GFCI trip function but does not measure loop impedance, leakage current or insulation resistance. Buyers needing those measurements require dedicated test instruments.

Highlights

  • Detects common wiring faults in standard and GFCI outlets
  • Confirms GFCI ground-fault device trips correctly for safety
  • Survives a 6.6-foot drop for jobsite durability
  • Operates from 32 to 140 °F across work environments
  • Tests 110/125 V AC 50/60 Hz three-wire receptacles

Specifications

BrandKLEIN TOOLS, Klein Tools
FeaturesGFCI Outlet Tester, Cat Ii 300v, Hand Powered, false
Height5.3 L x 3.8 W x 1.5 H inches
Width5.3 L x 3.8 W x 1.5 H inches
Length5.3 L x 3.8 W x 1.5 H inches
Weight1.9 ounces
Sports Team1 Piece

Questions about this item

How can I confirm the RT210 is working correctly after plugging it into an outlet?

Observe the three indicator lights and compare their pattern to the chart printed on the tester; it identifies conditions such as open ground, reverse polarity, open hot, open neutral, and hot/ground reversed.

What comes with the RT210 and do I need to buy anything else to use it?

The package contains the single hand‑powered tester itself; no batteries, leads, or adapters are required for testing standard or GFCI 3‑wire outlets.

Which version of the RT210 should I choose for 110/125 V AC circuits at 50/60 Hz?

The RT210 is a single model rated CAT II 300 V for 110/125 V AC at 50/60 Hz, so there are no alternative versions or capacities to select from.

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