I remember buying a black light 10 years ago and it basically didn't illuminate anything so I was always very hesitant to buy it. However, this light actually illuminates everything. In a 12x12 room it reaches every corner and is very bright. I can't honestly comment on the durability as I use them sparingly rather than daily but in my current situation I think these lights will last a while. I only wanted one, but I certainly don't feel left out at the price. I also don't know what witch lights are used to see blood or semen or whatever but it doesn't and I don't think commercial black lights do.