WORKSITE Pencil Electrical Test Screwdriver Pen Voltage Tester 3X140Millimeter Test Pencil. A Perfect Tool Kit for Home and Electric Industry Uses. Designed For Testing Power Cables, Circuit Breakers, Wall Sockets, Junction Boxes, And Fuses. Electricians, Maintenance, Service, Safety Personnel, and Homeowners Can Quickly Test for Energized Circuits in the Workplace or at Home. WT900402