During Christmas, the lights are often used. Christmas lights have a large number of bulbs, and when they fail, it is more troublesome to detect. At this moment, you need a Christmas light tester. This instrument allows you to easily ind any burned out bulbs on your Christmas lights. You can use it to locale your Chistmas light sting problem. It can fest bulbs, fuses, and the light strand. It incoporates a bulb remover which you can use to remove bulbs from Christmas light set easily. In addtion,it can be used as a 12V to 600V Ac power tester. The instrument's operating environment is 0' ~ 40C; relative humidity < 85%; indoor use. FEATURES 1.Non-contact AC voltage detection 2Adjustable detection sensitivity 3.Audible and visual indication 4.Tests fuse 5.Tests bulb 6.Retractable light bulb remover