Solid state electronics deliver a deadly but humane shock to both mice and rats. Uses (4) AA cell batteries (not included). Good quality alkaline batteries will provide about six months of stand-by power or up to 50 humane kills per set of batteries. Lithium batteries can double the length of stand-by power, as well as the number of humane kills. Battery recommendations are detailed in the operating instructions. Once the batteries are installed, bait the trap using any dry food as an attractant to the rodent (dry pet food, trail mix, peanuts). No poisons to endanger pets or the environment. Turn the main power switch to the "ON" position. The dual purpose red light will check the battery power by turning on briefly to indicate battery power is good. Mice and rats enter the chamber and are humanely exterminated with a quick but deadly shock; leaving no mess. Flashing red light indicates when you have a catch. Turn the power switch to the "OFF" position and tip the unit over the appropriate disposal receptacle to remove the rodent. Re-bait and return the power switch to the "ON" position. Easy-to-use and reusable. Not waterproof. Not for outdoor use when exposed to rain or snow.