G Green DrainWaterless Trap Seal, 4 Inch

Its good quality

edit (2025): after about one year of use it stopped working completely because rubber lost its elasticity. I started smelling sewer gas, after investigation took it out. Rubber hangs down leaving visible gaps between rubber, making it completely ineffective. The problem is with the largest one (4 inches).old comment:It works - somewhat. Each reduces sewer gas by a significant percentage, but not completely. I had to put in 3 at once to make it reasonably effective. Of course it depends how big your initial sewer gas issue was.One problem is that the silicone is soft and can be blown up by gas pressure.Its main advantage compared to other types that can be put inside a pipe is its resistance to dirt. I also tested spring and magnet traps, and they work perfect when they are clean, but they seem much more prone to things getting stuck in them (like hair) stopping them from working. Small water traps are perfect when filled with water, but they dry out easily and also have a tendency to fill with dirt.They should make a version with 3 seals in one.

Not strong enough and water goam can break out easily.

Incorrect information, the size specifically says 3.5 inches and not 4 as claimed

It is made of very soft plastic that insects, backflow or gas can push through

No it didnt meet my expectation