Permathrin and follow the instructions closely! Do not spray it directly on your skin!!! Best product made IMHO. The formula was developed for the military back in the begining of the Vietnam war. You should be able to find it just about anywhere you find hunting and camping supplies sold. Cabela's I believe still carry's it or you can order it directly from the company. If you do a Goggle search, the companies web link should come up on the first result page. I have used it while hunting for the last 20 years and have no trouble filling my taggs every year.