Designed for the demands of World Cup XC racers Christoph Sauser & Bury Stander this ultra-light & stiff carbon shoe offers Body Geometry performance & Boa dial adjustability. Light & stiff FACT carbon midsole runs the full length of the shoe with thermoplastic replaceable tread for confident traction Open-back lace guides for easy on/off Ultra-vented tongue for breathability Approximate weight: 335g (1/2 pair 42) New Lightweight Boa S1-M incremental zonal closure allows on-the-fly adjustments for a dynamic fit; L/R shoe forward rotating. Velcro front strap adjusts forefoot width & volume Four times more micro adjustment than a standard buckle closure Full BG features in outsole & BG+ High Performance Footbed combine to reduce hot spots & improve knee/foot alignment Engineered Micromatrix upper is light durable & supple fitting with welded reinforcement on medial heel for durability Replaceable high-strength braided steel lace