Review on Efficient Drain Spud #4223 by Aprilaire: Superior Quality for Optimal Performance by Kathleen Ledoux

In my case I didn't need this part. I just assumed the old one was leaking and sealed which meant it would crack if you tried to clean it. That's not true, it just sits in a hole with plastic tabs. In my case the filter falls off when you put the cap back on and some water leaks out during use. I have found that if you open the vent with the new filter before putting the cap on it will hold it in place and prevent it from moving. The leak was fixed and I kept the new one as a spare. 4 out of 5 because he does what he has to do.