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The new SERE 1 from Extrema Ratio features a partially serrated blade for cutting ropes, a belt cutter and a screw-pin shackle wrench

Extrema Ratio’s all new SERE 1 was developed together with special forces operators, martial artists and survival techniques experts. The knife is similar to a push dagger, but it has been redesigned as a multipurpose knife, suitable both for cutting and tip use.

extremaratio SERE1


The SERE 1 blade is specifically designed to be strong. Triangular planes on the tip converge to create a robust point. There is a slot in the blade that you can use as screw pin shackle wrench. A sharpened section (about an inch in length) has been incorporated in the spine as a belt cutter and is located toward the handle. The Extrema Ratio SERE 1 blade has a serrated area that is 1.6 inches (mm 40) in length. This serrated section was designed to be used for cutting ropes, belts, etc.


The Extrema Ratio SERE 1 handle is designed to fit between your index and your middle finger with indentations on the rest of the handle (both sides) for your other fingers. This gives you a very powerful grip. Plus the handle is textured to insure your grip is secure even if your hands are wet or you are wearing gloves. There is a substantial window breaker on the end that also incorporates a lanyard hole. There are two additional lanyard holes in the handle to give you more options. On the other end of the Extrema Ratio SERE 1 handle is an exposed metal area that can be used for hammering – it also serves as a thumb rest. The handle is slightly angled so it fits comfortably in your hand in a natural position.


The sheath for the SERE 1 is made of Kydex. Kydex is a durable thermoplastic that is tough, water proof, and chemical resistant. This hard sheath has an automatic retention to hold your knife in place. The sheath has been extended so that multiple lanyard holes could be placed all around the outer edge. This gives you great versatility. A lanyard is included. The sheath can also be used as a small emergency shovel. On the back of the SERE 1 sheath is an Extrema Ratio belt clip that is adjustable for different angles.

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Weight: 10.79 ounces
Blade Length: 4.37 inches
Total Length: 8.43 inches
Main Blade Thickness: 0.25 inches
Blade Material: Böhler Steel N690 (58HRC)
Handle Material: Forprene
Serration on the Blade: Yes
Main Grinding: Flat
Blade Finishing: Burnishing Mil-C-13924

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