How does the tether (included with the 1030 Plus) work?

I was looking at YouTube, and searched for "Garmin Edge 1030 Plus" just to see what people had to say about it.  I have never seen a video that mentioned using the tether, but I happened on a review by Victor Campanaerts, the current holder of the World Hour Record.  I was intrigued that a pro cyclist was doing YouTube reviews.

Campanaerts was unboxong the 1030 Plus, and he didn't bother to open the plastic bag that held the tether, but then he grabbed his current Edge (I think it was a 1030), held it up to the camera, and it had the tether installed!

The other interesting thing in his review was that he mentioned using the Edge 830 for racing, as it is smaller and lighter.

A big advantage of the 1030 over the 830 is navigation. You don't need that for a race.

So the tether is underneath the weather cap - is it not restricted?

correct the weather cap is shaped so that the tether can be installed but not get in the way of the weather cap : How to Install the Tether on an Edge Cycling Computer