Speedmetrics BTA mounts -- how do they attach?

Anyone have experience with the Speedmetrics BTA mount or integrated BTA + Garmin mount? I can’t tell how it actually attaches to the TT bars… The photos just show it resting on the bars with no attachment other than gravity/friction, which can’t be right. I do see a small hole near the rounded part, I’m wondering if that’s intended for threading a ziptie (and they just don’t show it)?

The product seems like a more robust version of the Zipp VUKA BTA bracket, which is attractive to me.

Ah found it in their Instagram, it’s just zipties.