Provent A Mite is the ONLY product that is federally approved for it’s use with reptiles and the only product that as undergone 14+ years of research.
While the other products will work with reptiles due to some similar ingredients they are not designed for reptiles, nor are they federally approved to be used with reptiles.
Also no one knows the long term effects of such products whether it is Nix, equate or others.
I will leave it to this, is saving a few bucks worth taking the risk of causing irremediable damage to your snakes????
PAM can be find here http://www.pro-products.com/miteandtemp.html and here http://www.entirelypets.com/proventamite.html