Unlike other watches that can take any strap to fit the lug width the C2 and C20 have a unique strap system. Therefore you will need a CWL strap/braclet or have to get one custom made.
On the leather version it is a double headed screw that keeps it in which is quite easy to remove.
On metal it is a long 26mm pin that holds it in place and I believe there is a collar in the middle so it i not as easy to remove as a standard bracelet.