Product review (5 stars): Good product for my application.
Worked great. Even after viewing Youtube video on how to install, I wasn't certain if the lines at the ends were O-rings to seal it, or just lines.  Turns out they are just lines drawn on the surface- when you've got it inserted correctly it is half way between the two lines. So if you were needing some longer version, and saw them for sale without the lines- it makes no difference really.