Beside the PDF below I have no additional information on the BRNO Zkb680 other than it is a firearm from the Czech Republic.
I think it is also called the Fox model 2. It is chambered in .222
I did find a shaky video of someone with one on YouTube. I have linked it below.[pdf-embedder url=”https://www.tngun.com/wp-content/uploads/BRNO-Zkb680.pdf” title=”BRNO Zkb680″]