Snap-on's 400 NM True UV Rechargeable Flashlight, No. ECFUVLEDA, helps locate leak detection dye on a vehicle. It has a 400 NM wavelength to locate A/C, oil and coolant dye leak detection and a 95 minute run time at constant power output. The UV light also has a focusing lens that enables broad and narrow searches. The set includes a plug-in charger, UV enhancing glasses and a 2800 MAH 3.7v Li-ion battery.