Originally Posted by TwinsPoppa

The best way I can explain it is its both directional and non-directional (mostly non-directional).

The tires are directional in that the groove that goes the whole circumference of the tire is always installed on the inner side. So, they are treated directionally for installation.

However, the tread design/pattern was designed to be effective in either direction.

So, in their own words:

"Thanks to this ingenious design, the Ultrac Sessanta is asymmetrical but its performance is not directional. This makes the tyre exceptionally quiet"

I think most people would agree that they are not really directional - since they can rotate effectively in either direction.