Kershaw Model 1550 Black Outs, designed by knife maker Ken Onion, with the new Speed Safe torsion bar technology are very quick to open with just a touch of the thumb stud . The Blade is made out of 440A stainless steel ti-nitride coated blade hardened to 55-57HRC . Black injection molded Polyamide handles mounted on double heat treated 410 stainless steel liners, with liner lock mechanism and removable pocket clip. Blade length: 3 1/4", Closed length:, 4 1/2", Weight: 3.50 ounces