The Grivel long extender bars worked just fine,I used them to fit my G-12 crampons to a pair of Lowa Civetta Extreme plastic boots (size 15!) They also worked, without being too long on, my size 13 leather mountaineering boots. My only disappointment is that Grivel does not offer these as an option when buying crampons or offer a trade-in or something, instead I paid an extra $20 and now have a brand new pair of regular bars that came with the crampons that I have no use for. Oh well...

Easy to retrofit. They do what they are intended to do. Wish Grivel offered them as an option during the original crampon purchase as their spec for the boot size fit for the regular bars is extremely optimistic. Can't imagine that most men using their Air Techs don't have to immediately buy these long bars.

Slight trouble trying to get it on. I had to remove the Antibot plates to add the extender bars. Once on, it works perfectly.