The Victorinox 54885 Swiss Army One-Hand Sentinel (Fine Edge Blade) Lockblade Knife with Clip has a main blade that can be comfortably and easily opened with one hand. That's what the big "hole" in the knife blade is for. When the knife is closed, your thumb uses this as you flip the knife open. Fine edge is easily sharpened when you need it. The Swiss Army knife carries Victorinox famous lifetime warranty against any defects in material and workmanship.