LED phase tester 100–250 VAC, individually tested, battery-free 2-in-1: single-pole phase tester for displaying voltages, also a robust screwdriver insulated blade made from special spring steel alloy, durable and long-lasting in use integrated LED for a reliable, visually recognizable display, even in brightly lit environments consistently high luminosity, 100 times higher than with glow lamps laser-marked serial number, lifetime guaranteeメーカー公称