No, you free to use use your own hardware.
For example we use in our kit Tekit
Screw: M4 type, 14mm
Washer: M4 type, 12mm
Rivet: M4 type
You can find this from your local suppliers or you can rely on your bodyshop specialist, because they usualy have different hardware to do this job.
We recommend to use our hardware, because it's a high quality products and we choose it especially for great view and installation. We never ever meet such flexible smooth and well-suit rubber like Rublok
, that is why we offer it to you.