The indoor lighting system is a compact, easy to setup electronic lighting system that provides optimum chronograph performance in an indoor or low light environment. It is portable and is fast to setup, just mount the light arcs and connect power. Its Patented electronic design eliminates light bulbs. The red LED (ON+ indicator lights indicates when you are ready to fire. The lighting system works with all Prochrono models. It comes with a 120 Volt AC adapter and will operate on a 24 Volt DC source (ex. two 12 Volt batteries wired in series.).