In what may have been the first lottery I have ever won, I was selected as one of 200 people–100 outside of Russia–who were afforded the opportunity to buy one of several Shirogorov/Sinkevich collaborations from the only authorized dealer for international buyers. This is another knife that defied my expectations and pushed me outside of my comfort zone. The Sebenza 21, the Emerson Mini A100 and the Benchmade Valet have been knives that instantly appealed to me due to their simple–perhaps plain–designs that rely heavily upon relatively straight lines. The Sigma, as you can see does not have many straight lines, but I decided to give it a chance. And I have no regrets about this decision. Curvaceous as the Sigma may be, every curve has a function: providing the user with a superlative grip, both comfortable and secure. The underside of the handle is the only straight line on this knife other than Shirogorov's signature plunge lines. The amount of contouring on the carbon fiber handle scales multiplies the comfort of the grip, tapering significantly toward the spine. The carbon fiber has also been extensively textured in a complex concentric circle pattern increasing the security of one's grip. The blade is unusual–at least in my limited experience. A triangular Persian shape with a slight bulge toward the tip. The flipper tab is almost in line with the cutting edge and is therefore less likely to obstruct any cutting on a flat surface. The flipper tab is barely proud of the handle yet provides authoritative and consistent opening. True to Shirogorov's reputation the action is extremely smooth and all the more satisfying due to the diminutive profile of the tab. The handle scales are solid carbon fiber without liners which makes the Sigma surprisingly light for size. The locking mechanism is composed of a titanium "tab" attached to the scales by two screws concealed under the pocket clip. There is a steel insert on the locking tab and lockup is firm at 20%. The pocket clip is perfectly functional and is a unique blend of a sculpted clip and a spring clip. The backspacer is anodized titanium and features a lanyard loop sunken into the scales. The backspacer only partially spaces the scales apart as the scales are milled in such a way as to serve half of that purpose. I would love to see fixed blade version of this knife made as it would be the perfect paring knife for the kitchen. Maybe someday.