For better or for worse, this ultra violet flashlight by 711-TEK performs very capably. I'm worried it might provide TOO much information! My two sons and I had an afternoon of discovery experimenting with what will and will not glow under this black light. So far, tonic water and urine come out the brightest. The flashlight itself is about six inches in length and requires 3 AA batteries, not included. I did recieve a promotional offer to try this product from Rank-Booster.