Instruction: Output yes if the supporting document can answer the given question. Otherwise, output no.

Input:
Question: My floor drain opening doesn`t quite look like 4". Almost looks like 3 and three quarters. Will this fit??
Document: Great looking product made by a local company. High quality material. Looks like it should last a long time. Fit like it should in 4 inch drain pipe. I don't rate to many things but this is worth the effort.
This installed into my 4&#34; floor drain in basement just fine and has a nice snug fit once tightened down. This is only put in the finished portion of the basement floor drains, so fi the water actually does back up, it will still flow out of the floor drains in the unfinished portion and eventually end up in the sewer before hitting the finished area. Our sewer is also below the basement floor level.
This product came ready to install..The hardest part was getting the cover offthe drain..Once that was done.The seal fit into the pipe opening.. Replace thecover and you're done..
As stated in another review, this isn't for a sewer line, this is for a floor drain. Product is well built, and I don't doubt it will work well. Will buy another when we move to a new house soon.
During very heavy rainfall, I get a little bit of water in my sump area in my basement. This valve like guard allows the water to drain down, while also preventing any main line backup from entering the sump area. I just replaced an old one with a new one, and it has never failed me over the years.
Putting one in the sewer drain wouldn't help in that case as it would just end up pushing the sewage out the toilet in the basement, or worse, out of the bathrooms in the upper floors. Putting a check valve such as this in a sewer line may also violate some local ordinances, but I didn't look that up since I wasn't putting it on the sewer line anyway.
The Seller didn't mention that this one needs to be checked periodically to ensure it's working properly. That means you shouldn't instally it in a sewer line where you would normally expect to install it. It's made for basement floor drains so ground water won't back up into your basement when the water table rises. If you want something for the sewer line to protect your home this IS NOT what you should buy!
This is a good product but I use this to take excess water out of my basement trap.I remove the sewer pipe 4 inch cover so the water drains out into the street sewer system. There is a backup plate which can stop any sewer returning into the pipe.However, this plunger is always down and sewer odors can be emitted.
Only problem I had was trying to use pvc pipe with a donut for 4&#34; cast iron. When I changed to thin wall all worked fine. The Gen. Wire products are good quality and I think the first check valve I installed (same as this product) lasted 15 years or more.
Installed, which was not difficult but didn't realize how much you had to turn screws to tighten in the drain. Waiting to see if it will do as advertised.
Answer: no