Williams Blade Design OZK002 Osoraku Zukuri Kaiken 4.5" Knife The OZK series is a lightweight, compact, fixed blade using our proven Osoraku Zukuri blade shape, and professional-grade Sleipner tool steel. The 3D milled neutral handle provides excellent grip no matter how you choose to hold the knife. A slim, lined, kydex sheath, paired with a Tracker Dan clip, make for a variety of discreet carry options. The result of decades of experience, the ideal EDC blade.