Ideal for walking, hiking and running on snow-packed trails * Securely attaches to running shoes, lightweight hikers, everyday shoes, and snow boots * 3/8-inch-long spikes (1 cm). 12 spikes per foot on SM to XL. 10 spikes per foot on XS * Spikes made from heat treated 400 stainless steel. 2-year manufacturer"s warranty. Weight (per pair): SM - 12.2 oz. MD - 13.6 oz. LG- 14.4 oz. XL - 15.6 oz * SIZING (for Hiking Boots & Tennis Shoes): XS - US Youth 1-4. SM - US Men 4.5 - 7, Women 5.5 - 8.5; MD: US Men 7 - 11, Women 8.5-12; LG: US Men 11-14; XL - Men US 14-16