Extrema Ratio Ultramarine Fixed Blade Knife (5.875" Black)

MSRP: $791.95
Our Price: $650.90
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Item #BHQ-46535 Online Only


  • Overall Length:11.625"
  • Blade Length:5.875"
  • Blade Thickness:0.25"
  • Blade Material:Bohler N690
  • Hardness:58 RC
  • Blade Style:Dagger
  • Blade Grind:Flat
  • Finish:Black
  • Edge Type:Serrated
  • Handle Length:5.75"
  • Handle Material:Nylon
  • Color:Black
  • Weight:13.90 oz.
  • User:Right Hand, Left Hand
  • Sheath:Nylon
  • Knife Type:Fixed Blade
  • Brand:Extrema Ratio
  • Model:Ultramarine
  • Country of Origin:Italy
  • Best Use:Diving, Tactical
  • Product Type:Knife


The Ultramarine by Extrema Ratio is a high end dive knife crafted for elite military service. The thick Bohler N690 stainless steel blade is coated with a Mil-C-13924 finish for a non-reflective, corrosion resistant finish. The dagger blade features partial serrations and an integrated strap cutter. Nylon wrapped handle provides a slip resistant grip. Included is scuba ankle sheath for ease of access.


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