Tired of having an LED light string that only partially lights? Wish you could repair your lights instead of replace them? Well look no further than the LED Keeper, the only kit able to diagnose and repair most LED light sets! The LED Keeper uses insulation piercing technology that creates mini-circuits, illuminating functioning sections of the light string, and therefore allowing you to identify the problem area through the process of elimination. Use the two included place markers to identify which bulb or socket is not functional, the included bulb puller to remove the bad bulb, and the two replacement pods, which maintain the electrical balance of the string, keeping it lit. For a step-by-step demonstration, check out the attached video below. Requires one 9V battery, which is included.