The crampons with either Classic or New Classic bindings now have a new flexible regulation bar for improved fit and performance on walking boots: flexible and elastic, allows the foot free movement without over-forcing or stressing the bar, even on extended use. The flex regulation bars are made of multi-ply stainless steel and work just like a car's suspension springs. Note: the Flex Regulation Bars can be used on all of Grivel's crampons. These are sold in pairs.