Tested in the Himalayas * Eleven heat treated carbon alloy traction spikes (3/4 - 1/2 inch high) can handle up to 2 metric tone of pressure equivalent to 400pound person running on hard surface * Ergonomic Spike Plate System provides superior stability in comparison to individual spike bits and reduces muscular fatigue * Aggressive heel spikes provide excellent traction when descending or trail running * Durable elastic harness and Velcro strap will keep the product stay on your shoes