nautilus o-ring round or square?

[FresnoDan]

I'm replacing my 18" oring on my stainless steel (old)Pac fab DE filter. I took it apart and the oring is square but at the pool shop the new one is round. Does it make a difference or is this OK? Thanks for any info.

 

[JettaGLi16v]

To my knowledge, the Nautilus SS orings are round originally,
and they will take on the shape of their location..

If the overall diameter and thickness are close, you may as well lube it up and give it a try!

-B.