Nike Air Zoom Winflo 5-Men's Running Shoe-TARGETED SUPPORT. ULTIMATE RESPONSIVENESS.-The Nike Air Zoom Winflo 5 Men's Running Shoe provides a responsive ride and durable, multi-surface traction underfoot. Up top, engineered mesh delivers strategic support and breathability, while a partial bootie offers seamless comfort as you hit your stride.-- Full-length engineered mesh creates a breathable, supportive fit.-Zoom Air unit delivers responsive cushioning.-Co-molded Cushlon crash rail provides a smooth transition.-Dynamic Fit technology integrates Flywire cables with the laces to wrap the midfoot and arch for a glove-like fit.-Full-length, solid rubber in a Waffle outsole is durable and provides great multi-surface traction.-Weight: 9.5 oz. (men's size 10) Midsole Offset: 10mm Last: MR-10--
A:all shoes would open slightly. This one is pretty snug. I have two pairs of these and have done 1 full marathon and 2 half marathons in this and it is holding good.