FLEX BAR: The crampons with either Classic or New Classic bindings now have a flexible regulation bar for improved fit and performance on walking boots. It allows the foot free movement without over-forcing or stressing the bar even over 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