GFI OUTLET TESTER GFI-3501. Easy to use - simply plug tester into any 110/125V AC ground fault receptacle and press black button. Detects 6 common wiring errors in standard & GFCIprotected outlets. Seperate GFCI test button tests standard outlets to GFCIs. Sold as each. For 110-125 volt AC. Red. UL listed. Manufacturer number: GFI-3501. Country of origin: China. Distributed by Gb Electrical.