Hello, are supplied. Mfg

The T-slot fits perfectly on our Thule Wingbar Edge. Holds perfectly. The instructions do take some getting used to, but once everything is installed, it's pretty quick. We have up to 4 carriers in operation.

Everything is supplied. But be careful whether the roof racks have a rectangular or an oval diameter, that seems to play a role.
And if I remember correctly (I don't have a car anymore) the part was very good, but had the most miserable assembly instructions I had ever experienced. It took me a few youtube videos to figure out how to mount it.