LRI's Proton PRO uses a two-beam feature to provide both an incredibly powerful ultraviolet light for easy florescence checking in broad daylight and a smaller secondary white beam for general purpose use using a single AA battery. LRI's popular Freedom® digital circuitry provides intuitive one-button access to full-range brightness control and safety strobe functions for the secondary beam. One AA battery will power the Proton for approximently 1.5 hours or up to 250 hours at reduced brightness.