VKB-SIM

I loaned my Pedals to a friend while out traveling and they are missing a nut on the center base that connects to the arms that connect the pedals to the base. My local store just has SAE nuts which don't seem to work so I will need to order online. Are they M4 or M5 nuts?

Nothing was posted so this is just for the next person who comes along via search or something else:

If you don't need to disassemble the arms often, M5 Nyloc nuts work pretty well.