Car is a 2016 CX-5 with factory roof rails. Great Car!

I have a set of aftermarket crossbars from another vehicle. They are the right size. What doesn't fit is the cleat (? - not sure if that is the right name) that goes in to the roof rails. The 'T' section that fits in teh groove it too small.

Can I buy another set of these cleats that will fit or is there another way to attach the crossbars?

Thanks