Quote Originally Posted by Vapor View Post
(I don't think anyone else tested the thicker o-ring, was I the only one to get it?)
No, all testers have it and it is also a regular part that comes with the block.

Quote Originally Posted by Alexandr0s View Post
But less restrictive than the XT I presume?
According to another test from a user here: yes. 5.1 LPM vs. 5.9 LPM

Quote Originally Posted by churchy View Post
I beleave that these block samples were not final production version, but ones that were sent to different testers?
(remembering sentence that mounting system will be fixed in final to fix incompatibilities with few motherboards and such ..)
Shoggy: what thickness O-ring final retail version of block includes then compared to these samples?
The only fix that we did was to change the size of the laser cut for the bolts since it was a tad too small so it was hard to get the block mounted on the board.

The default o-ring is 22 x 1.5 NBR 70 while the thicker o-ring (always included) is 21.95 x 1.78 NBR 50. The thicker o-ring should be used with care since it will bent the base much more than the small one. It depends a little bit if the thicker o-ring will gain a better cooling performance. Normally the default ring should be the best.