the primary ingredient is derived from a plant cant remember the name off hand, but they also offer earth scented pads too for those afraid it may spook their target animals, ive hd deer as close as 30 feet away and they didnt act weird or even give me a second look. they sell refurbished unit for like 17 bucks which is what i did and it works great... im gona buy an extra one in the next few weeks.
