Oatey Oatey-43745, No Size, Black

Works exactly as described

The rubber is very soft and flexible, so I do have any doubt that water can pass downward through this. And it seals up well at the pinch point, so insects and odors are not going to come upward. I am using the 3" one, for a floor drain, just to be clear. My drain is made of pvc and the fitment is nice and snug.

I have a upstairs shower that has a faulty P trap and often smells bad. I had to clean the drain every couple of weeks only for it smell bad again. This drain trap fits perfectly in the drain pipe and immediately blocked the smell. So far no issues with slow drainage during or after I take a shower. I would recommend however just manually inspecting it every now then to make sure no hair or gunk remains on the drap trap after a while. Its easy enough to remove and give it good clean and or rinse and then putting it back in place. I like that no tool are required for installation except for a screwdriver which you need to remove your existing shower drain cover. Definitely money well spent as my P trap is not accessible to replace or repair without a major remodel. So this is a cheap and easy fix.

The seal around the outside in the three inch drain is good but the actual opening of the silicone that allows water through doesn't sit closed nicely. Instead it's a bit warped and has little openings and since I bought this to prevent gases from coming up the drain I'm quite disappointed.

I think this drain seal is great and easily worth the price. It stopped odor and drain fly problems in my 4” basement floor drain. Works great with condensate lines as well as larger flows. I’m on about 6 months with mine. I expect it will need replaced every few years or so. But it’s easy put in and take out, no tools. “Doing the job right” costs thousands. So I’m pleased.