Instant purchase welcome, no comment needed! Please be aware that as this is an imported product, there may be minor scratches, marks, or scuffs that do not affect its functionality. Simple packaging. 21 LEDs A black light that strongly reacts with fluorescent substances, etc., and glows brightly. - For curing UV resin for nails, etc. - For short-term charging of phosphorescent materials such as glow-in-the-dark lures. - For illuminating fluorescent paint art. - For charging glow-in-the-dark fishing tackle. * When irradiated on fluorescent substances that react to each wavelength. This is not a light that illuminates the darkness. We cannot accept claims that something does not react. Wavelength: 395-410UV 3 AAA batteries (batteries not included).