Huh. I've noticed several times when I click some links here, all I get is a new window with about:blank in the URL window, and nothing ever loads. This is the case with both instances of the posted link.
If I CnP the link to a new tab window, the link works and the site loads properly.
On point, I have a black mesh KO band from some Amazon vendor that's— ok. It shows some less-than Apple polish on the magnetic tab (i.e. looks cheap) and the magnet isn't as strong as the Real Deal. After several minutes it's a little loose and requires tightening.
Otherwise it's nicely done, but still a marginal purchase even for $12.