Kahtoola"s micro spikes are a pocket sized traction system that allow anyone, of any age to get out and safely enjoy winter. * These slip on spikes dig into all types of terrain-ice, snow, wet rocks, concrete, and scree. Extremely durable, they attach securely to your footwear and require no special buckles or straps. * Sizing: Small:youth4-5.7, Women 5.5-8.5 Med: Women 8.5+, Men 7-10.5 Large: Men 10.5-14, XL: Men 14+