Crampons similar to boots are rated on their flexibility and by how much support they provide.
Crampons for flexible boots.
C1 crampons that are flexible with simple straps and usually ten points.
These crampons are known as basket binding or flexible crampons.
Crampons are graded c1 c2 and c3 relative to their flexibility and general compatibility with different styles of boots.
Basically if your boot bends so much when you take a step that it can wiggle its way out of the crampon then you ll need stiffer boots.
No crampons are suitable for b0 boots flexible walking boots.
Bring along your boots when shopping.
For highly flexible boots get crampons with a flexible center bar that connects the front and back.
You want what is right for you and your conditions.
Crampon boot compatibility use b0 boot flexible b1 boot semi stiff b2 boot fully stiff.
In general the lower ratings are for snowy backpacking and the higher numbers are for alpine ice climbing.
You can wear aluminum crampons with sneakers and strap on bindings for light mountaineering or glacier travel just make sure the flexibility is similar.
Flexible crampons c1 on the other hand are primarily designed for hiking and mountaineering on flat and semi steep terrain glacier travel and similar.
They are designed to fit boots that are fairly flexible but will still fall off if you wear them on flexible summer hiking boots.