Product review (4 stars): It's an O-ring!!!!!
What can I say, it's an O-ring, but when I got the automated e-mail asking to review it, I just had to say something.

Here it is....

The O-ring fit the device it was designed to work in, thereby preventing a leak and a flooded basement.  I recommend that if you need an o-ring and this is the size you are looking for, buy it...  Buy it quickly....