The 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 ascents in the mountains. The revised speed lacing system gives a sure hold across the instep, and the plush leather lining inside the boot is instantly luxurious and comfortable. The SL is built using a 2.8mm Sherpa leather (the toughest and most waterproof of any full grain leather Scarpa uses) impregnated with HS12 and build as a one piece construction for durable weather protection. The SL also uses the Vibram biometric trek sole for traction and support when carrying a large pack. The leather and 37.5 lining (and lack of membrane) make this a brilliant boot for warm weather trekking. Crampon Rating - B1 Sole - Vibram Biometric Trek Last - TM Upper - Sherpa HS12 Leather Lining - Leather & Cocona Weight - 1612g Mens 42 Insole - Performance Flex Plus