[Closed] ROHLOFF - Emergency!!

If you ride a Rohloff, you'll know what I'm talking about so please read on..........

I'm meeting my mate tomorrow halfway down the Pennine Bridleway. He runs a Rohloff and has had an issue changing gear. He reckons he's sorted the offending cable, but in case, he's asked me to take a spanner so he can change gear by moving the hex-head behind the cable pulley manually. Problem is - he's no idea what size the hax-head is. I can't find it in the instructions - can anyone help??

Thanks in advance!