I bought a cheap one about 4yrs ago with the hopes that it would help me find coyotes in thicker cover more easily, as well as archery deer. Didn't work, so I bought a more expensive one. Didn't work, so I bought a more expensive one. Didn't work.

I wasted about $500 on these d@mn things, all told, and I can't say that any of them work better than the other, because I can't say any of them work at all. I suppose if you sprayed a few hundred dollars worth of lumenol all over the field, then the blood would luminesc under black light, but as it is, these things are a waste.