Drphil - they attach to the spinlocks by means of a handle underneath the humps near the outside bottom edge very similar to the handle that attaches the hardtop to the spinlocks. You then have Velcro straps that attach from a mounting point to the rollbar (you can see the mounting point for the Velcro in the bottom picture left and right of center at the bottom of the humps.
Once properly attached, they're not going anywhere at speed. Weight is minimal.
It's about a 5 minute operation to attach and is easily done with one person.
I have several sets for my Boxsters. I like the look when installed.
These are priced well. If I didn't already have what I need, I'd have bought these first thing this morning.
One of you guys better grab them before I decide I need another set.
