Ok, so as the title suggests.. I had a snake come up in my toilet the other day. Fairly large one and I'm assuming it got in through the ventilation vent on the roof, although I'm not 100% sure!! I am in search of a product that is a one way flow product that connects to the bottom of the toilet (mf2) and allows waste water to be flushed but nothing to come back up. I am connected to a septic tank and live in a mobile home. The pipe connecting to the toilet is 3" I've found only 2 in a about a week of searching one is totet.com , but read a number of horrible reviews all saying that they ordered/paid for the product and nothing was ever shipped. The other one I found is a company based out of Europe and they don't have the correct connection size for mf2. They only carry 4" and i need 3" Not to mention I'd rather purchase something at least here in the US. I realize that I can ( and will ) climb up on the roof and find the ventilation vent and make sure its secure from anything entering, but I'm here to tell you.. Thats not going to be enough for me .. Seeing that snake with his head about a foot 1/2 out of the toilet was life changing lol.. So if anyone can point me in the right direction.. It would be Greatly GREATLY appreciated!!!!