IMPORTANT: When using tools and electrical items, basic precautions should always be followed. Most importantly, Read and Follow all Safety Instructions provided by the Manufacturer of the Miniature Light Sets. The LightKeeper Pro is a tool designed to be used with miniature light sets only. The LightKeeper Pro IS NOT A TOY. To avoid injury or accidents it is recommended that the LightKeeper Pro should not be played with or placed within the reach of small children. All references in the following instructions to "Outlets" are to a 120 Volt AC power source. When replacing any batteries, DO NOT mix old and new batteries DO NOT mix alkaline, standard (carbon-zinc), or rechargeable (nickel-cadmium) batteries. When disposing of batteries, DO NOT dispose of batteries in fire; BATTERIES MAY EXPLODE OR LEAK.