V2 Aero XL150S Skating Roller Ski Bundle NNN Bindings & Speed Reducers, Fully Assembled Lightweight aluminum shafts support skier weights up to 200 lbs. Reinforced shafts available as an option. Long-lasting 6-inch (150mm) inflatable tires deliver a smooth air-cushioned ride on both smooth and rough surfaces. Pre-mounted V2 ATR150XL Speed Reducers, a highly efficient lever-activated braking system, to control your speed on downhills. Custom-mounted Rottefella NNN bindings, which are compatible with Alpina, Rossignol, Fischer and Madshus XC boots. Please send us a product customization request including your height, weight, shoe size, binding type (NNN, SNS Profil or SNS Pilot), and braking system choice (emergency brake or speed reducers).