This economical and efficient transistorized handheld ultraviolet lamp provides rays in the UV-A (blacklight) range (365 NM to be precise), perfectly matched for use with our detectable substances like our UV thieft detection powder. Its convenient coat pocket size makes it as practical in the field as in the lab. It also has a standard white flashlight bulb built in. Uses four AA batteries (not included). Note: A small segment of the population is sensitive to radiation in this region of the spectrum and may experience adverse effects. Size: 2" x .75" x 6".