In looking into the cramp-o-matic G-12's...
In looking into the cramp-o-matic G-12's I noticed that they offer the XL cramp-o-matic. I wear a size 12 boot. Will I need the XL? Thanks for the info.
I did some checking on your question and the one-size version of the Grivel G12 Crampon will fit Euro size 36-47 shoes which converts to a US size range of size 3 to 14 so you should be all set with the one-size version. I hope this answer helps.
I believe that will actually be more like 6-13 in US sizes, European sizes have smaller increments to allow for more sizes.
Hope this helps.