SL ActivThe SL is the 9th generation of this classic, really tough trekking boot, now even more luxurious and comfortable, while still being fully compatible with C1 walking crampons. The new SL is now built on the latest TM last shape, giving an improved heel fit and closer fit across the forefoot. The redesigned upper uses a soft nubuck leather cuff with a cut out at the achilles, as well as redesigned flex zone, giving greater comfort on long descents and