FlashCat UV Flashlight, Bright 21 LED, 385nM Best Quality Wavelength to Locate Pet Stains, Make Scorpions Glow, Detect Engine Leaks and Legal Currency BEST UV WAVELENGTH for detecting dry urine stains, 380-385nm 21 LEDs for brighter visibility DETECT DRY PET STAINS on floors, walls, carpet SPOT SCORPIONS before they spot you, rat and mouse urine becomes visible ENGINE LEAKS - AC, Oil, Antifreeze are easy to see DETERMINE REAL CURRENCY in a flash! The newer large bills have a security strip, visible in seconds.