Louis Garneau Men's Ls-100 fabric-and-synthetic Ergo Air II reinforced nylon outsole with patented multivent system: Provides excellent rigidity and increased ventilation HRS-90 with 0.4 mm membrane: Maintains heel positioning and reduces loss of power BOA L4 single rail quick attach system and forefoot velcro closure: Quick attach, distributed pressure and ultra light Synthetic leather and cycling mesh upper: Provides comfort, good support and breathability Interchangeable COOLMAX Ergo Air Cool Stuff blue and Hot Stuff red insoles: Patented ventilation system