The Tracerline OPTI-LUX 365 LED leak detection flashlight provides pure UV light for optimal fluorescent dye response within a 25' range. It can be used for all A/C and fluid system applications. The flashlight brightly fluoresces both green and yellow dyes, even pinpointing high-mileage, dirty diesel engine oil leaks. It is powered by one rechargeable Li-ion battery to provide four hours of continuous inspection. The anodized aluminum lamp body resists corrosion and stands up to years of heavy shop use.The flashlight comes complete with a lanyard, belt holster, two rechargeable batteries, smart charging cradle with AC power cord and UV-absorbing spectacles, all packaged in a padded carrying case.