Originally Posted by Ceathreamhnan
Sightron supply a tiny Allen key with the SIII 10x42. I've been trying to find mine to measure it; it's so small it's too fiddly to bother with regularly.
I will dig mine out tonight and check. Re the fidly bit - you're right it is tiny. I bulked mine up with white parcel tape so I can at least pick it up from the bottom of the tin and see it easier amongst the rest!