Hey guys just got a new line of flash lights and 1 of them emits a UV beam and in the dark it turns a blood trail into a florescent reflection, and can do the same with urine. So if ever you wanted to see if a scrape was fresh, or if you happen to lose the trail of a wounded animal near dark this unit can be very effective in helping you track that downed animal. I didn't have any blood handy when I recieved my new sample, so I went to the boys bath room and looked for" traces" of urine in the dark and by god it was everywhere. Was neat to however my wife wasn't all that pleased!! This new brand is called premier light, very simular to surefire only way less dough. FS