Heel plate bolt

I have lost one of the bolts that hold the heel plate on. Does anyone know what size/name of the bolt I need to order to replace it.

Ta

 

which year is it?

 

I forgot the most important bit ! It's a RR-7 (2007)

 

M6 thread x10mm long. Can't see if there's a collar without removing it, but I wouldn't worry about than. Just try to find one with the same head. Mine are a 5mm Allen head.

 

Thanks for your help.