Now you don’t have to discard a string of non-working mini lightsâ€”just use this handy tool to detect and repair faulty bulbs. It sends an electrical pulse through the string and repairs problems associated with defective shunts, often the cause when an entire section of lights goes out. Easy to useâ€”an LED in the tip makes it easy to work in dark areas. Also includes voltage detector with sound, bulb/fuse tester and bulb remover. Comes in a package that doubles as a storage case for extra bulbs, fuses, tape and more.