Drain Backflow Preventer 4 Pack, One Way Valve for Pipes Tubes in Toilet Bathroom Floor Drain Seal Resist Smell and Bugs, 1.97" Silicone

This sounds like a great option for my houses old drains/plumbing. Many of my drains do not have traps and sewer gases/insects have a portal to my house using the path from the drains. I've been using standard rubber plugs for years but, was hoping these gadgets would solve the remove-replace plug process when you need to use the drain. The rubber sleeves fit snuggly in the drain and the metal covers loosely fit over the top but, don't stay in place very well. This is not that big of a problem. The real problem is: I put one in my shower drain plug and unfortunately the water starts to build up in the bottom of the shower because the rubber sleeve does not open it's little rubber baffle very well, so draining is slow. I do not like this because when your shower fills up with water it traps soap scum and misc. people pieces and causes rings, grime, mildew, etc. I tried to modify the little rubber baffle sleeves by carefully cutting with a pair of scissors but could not find the magic/perfect cut that would allow better drainage yet keep bugs and odors away. I will keep the remaining three (I cut up one and received four) in case I find a use for the rubber sleeve/baffle. I'm sure there is some possible use for this for an RV, make-shift temporary tub/pool, etc.

I bought this for my shower to prevent a odor that comes from the drain. The inner diameter of the pipe is 2" and this is supposed to be 1.97" (the metal insert is larger). Calculating everything out it should have fit fairly snug. After it arrived I found that the dimensions were actually smaller so it was fairly loose in the pipe. I figure I could engineer something for a tighter fit and did (silicone). My shower head is 2.5 GPM and the shower began immediately filling up. This Backflow Preventer has no practical use in the home unless its being used with a very low volume of water. I am assuming this was originally made for a pipe with an inner diameter of 50mm.

This item will work provided you have a long down tube in the drain. It installed nicely in the shower, but the tub had a short down tube and then a quick right angle, so I could not get it to work in the tub.

The Backflow presenters worked very well. Fit with ease and were easy to install in my drain. It even prevents anything from coming back up the drain.

Don't bother, Good idea but bad design. Blue sleeve does not lock into placed, I can easily tell that it would just slide right off into the drain with any water pressure. This will be returned. Very bad design for such a simple concept.Blue sleeve should fit into first metal piece then the top should lock on top of it.

the description says 1.97 inch I would think that is the inside of the pipe but its not. it is closer to O.D. of the drain pipe. this fits in a 1.5 inch plastic pipe not 2 inch. I found some bushings at the hardware store that got them to fit.

Silicone sleeve opening is bigger than the metal ring, therefore, when installed it comes right off and get a stuck in a drain. Waste of money, I lost 2 silicone sleeves down the pipe, so now can't even return the d*** thing

Used for open drain in bar area. Keeps the smelling oder from under the bar sink from everyone smelling them.