Competition Electronics Indoor Lighting System, Fits ProChrono Chronographs Indoor lighting system Fits all ProChrono digital chronographs Provides optimum performance indoors or in low light Utilizes 72 infra-red LEDs which emit light that cannot be seen by the human eye Portable & fast setup Patented electronic design eliminates the need for light bulbs Red LED "on" indicator lights 120V AC 60Hz adapter input 24V DC 200 mAh adapter output 200 mAh power consumption 120V AC adapter* included *Can also operate on a 24V DC power source, such as two 12V batteries wired in a series. Whether you shoot indoors or out, you'll need this supplementary lighting kit at some time. It's a good idea to have it on hand right from the start.