The Subrosa is a collaboration project between Ken Steigerwalt and Matt Lerch. They have patent pending status on this mechanism. They sold the manufacturing rights to Benchmade, who produces factory versions utilizing this mechanism. The key elements that make this assisted mechanism a cut above are the two titanium leaf springs connected together with a hardened roller that engages on the blade. Because the roller follows the blade during the opening and closing motion, there is little to no wear to the components. Tumble finished S30V stainless steel drop point blade with single thumb stud. Milled titanium frame with titanium barrel-type spacers, and bead blasted stainless steel tip down clip. Comes with original box. Has a couple light scuffs and scratches, great condition otherwise.