Winter runners delight! You can now stick to that winter training plan thanks to Kahtoola NANOspikes. Offering incredible grip on icy sidewalks and trails, these simple-looking traction devices give you no excuse but to run. NANOspikes are ideal for walking, hiking, and running on snow-packed trails. New ergonomic elastomer harness is thinner and lighter than ever-without sacrificing strength or durability-and stretches over the entire foot more uniformly for improved comfort. Overmolded eyelet technology permanently fuses the stretchy, flexible elastomer material to a harder polymeric insert for greater durability. Eyelets are set further into the harness to increase durability and create a more streamlined fit that better conforms to the contours of any shoe or boot. Entirely new spike design features tungsten carbide studs with stepped and tapered shock-absorbing cleats around them-the studs offer superior wear resistance and unrivaled bite into ice while the cleats effectively engage other types of terrain. Ten 0.21-inch spikes per foot ensure complete slip resistance; textured bottom enhances traction on non-icy terrain. Upward Traction technology is comprised of multiple small cleats that grip your shoe's tread to effectively keep NANOspikes in place. Low-profile design encourages a comfortable, natural stride. Hinged front plate flexes with the foot for enhanced fit and durability. Built-in Snow Release system sheds snow with each step to avoid balling. Glove-friendly with no buckles or straps to tighten. Convenient carrying case included. Sizing (for running shoes and hiking boots):. ~ Small, Men's 6-8 Women's 7-9. ~ Medium, Men's 8-10 Women's 9-11. ~ Large, Men's 10-12 Women's 11+. Weight: 8 oz.