Kershaw Whirlwind ST A/O .This knife is a linerlock with a Sandvik 14C28N stainless steel partially serrated blade with thumb stud. Features Speed-Safe torsion bar mechanism for assisted opening. Black polyimide handles offer a solid grip. Stainless Steel liners reinforces the handle. Removable stainless pocket clip. Designed by Ken Onion Made in the USA.