Bosch Rotak spare part??

[Bfellow]

Hi guys,

My mower gave up half way through mowing, it's a bosch rotak. I believe that the part I'm going to attach from google images is what I need but I can't seem to find it anywhere. It's the plastic circular bit. Is there any other part from any other brand or model that I could use instead?

Also if anyone even knows what the part is called? It'd help me find it

Thanks!

 

[Rivets]

How about giving us a little more info on your unit, as we are all over the world and some of us are not familiar with all brands. Units model and serial numbers would be of great help.