Extrema Ratio NK3 K Neck Knife Fixed Blade Knife 6.75in Overall 2.75in Tanto Blade Glass Breaker One Piece Black Mil-C-13924 Burnished N690 SS Black. 75" overall. 2.75" tanto blade. Finger ring. Glass breaker. One piece black MIL-C-13924 burnished Bohler N690 stainless construction. Black Kydex neck sheath. Boxed. Specifications for Extrema Ratio NK3 K Neck Knife Fixed Blade Knife: Manufacturer: Extrema Ratio Knife Application: Neck Knife Package Contents: Extrema Ratio NK3 K Neck Knife Fixed Blade Knife Extrema Ratio 04.1000.0213BLK: NK3 K Neck Knife Fixed Blade Knife 6.75in Overall 2.75in Tanto Blade Finger Ring Glass Breaker One Piece Black Mil-C-13924 Burnished Bohler N690 SS Construction Black Kydex Neck Sheath Black