I have used these for years now and they work extremely well. My house never smells while I am using these. I'd buy them from BAS only. The first one I ever bought I got ripped off on from Amazon. I have got multiple ones from BAS now and they are legit and I am so glad they are selling them. If you are on the fence about getting one, I say go for it. You will not smell anything coming from your room or tent. These are perfect!