From the Manufacturer Tests standard 3-wire and GFCI protected 120V outlets for 7 common wiring errors. GFCI function tests GFCI and standard outlets wired in series with GFCI outlets (e.g. multiple outlets in kitchen or bath). Neon lamps indicate 7 common wiring conditions with the wiring condition legend easily visible on top and bottom of tester. Tester offers a compact ergonomic design with over-molded rubber grips. UL/CAS/Intertek, CAT III 300V Operational Voltage Range: 120V AC Frequency: 60Hz DURABLE: Hi-Impact Resistant ABS housing with soft over-molded rubber grips with a compact ergonomic design (GFI6302 and VD6504) QUICKLY READ: Bright color-coded neon lights for easy visual indication (GFI6302) TESTING CAPABILITY: Standard 3-Wire and GFCI protected 120Volt AC Outlets. Frequency (Hertz) 60Hz (GFI6302) GFCI FUNCTION: Tests GFI Outlets and standard outlets that are wired in series with GFCI outlets (multiple outlets in kitchen or bath) RATED: 10 ft Drop and 250 lb Crush, CAT Rating III 300V, C-UL US, CE-Marking and recognized by Occupational Safety Hazards Association (OSHA) as an National Recognized Testing Laboratory (NRTL). 10 ft Drop and 250 lb Crush WARRANTY: Sperry Instruments Backed Limited Lifetime Warranty