Reebok R Crossfit Nano 3.0 Womens Training/Fitness Shoes Synthetic The Reebok R Crossfit Nano 3.0 is the most versatile training shoe created by Reebok and is perfect for cross-training and the toughest workout sessions Seamless 360-degree polyurethane cast for lightweight, engineered support and durability with a breathable mesh underlay and tongue for comfort and ventilation The breathable mesh ETC anti-friction lining reduces abrasion and heat build up The Dual Density platform offers rearfoot stability and impact protection RCF natural last enables full foot dispersion for greatest stability with medial/lateral rope guard and multi-directional outsole splay zone