This heavy duty survival knife features a 2.5 mm thick 12C27 sandvik blade, a thick serrated area, an integrated 4 seasons 110 db survival whistle and a shackle key. The handle features a non-slip area (colored area) and can resist extreme temperatures (-40c to + 80c). Opinel No8 is the most versatile size in the ever growing line of folding knives. This knife is small enough to be used as a pocket knife and its 3 1/4' blade prevent it from being considered a weapon in most states (check with your state).