"Extrema Ratio Sethlans" is a fixed-blade work knife created to deal with a wide range of situations, suitable for survival, bushcraft, prepping, but also as a backup blade. The Sethlans was designed in collaboration with Daniele Dal Canto, Master Advanced instructor. The Sethlans is available in two versions with two different types of steel. Stone Washed version using böhler N690 heat-treated to 58 HRC, chosen for the reliability it has demonstrated over the last 20 years due to its resistance to oxidation and durability of the wire. Black version that uses D2 steel, heat-treated and cryogenically at 60 HRC, which has a high regrinding capacity even with makeshift tools. To give greater hardness and resistance qualities, the blade is coated with the new Teflon-based product "EXP DARK", proposed by Extrema Ratio. The knife comes with G10 scales that feature the ergonomic design characteristic of Extrema Ratio handles. They can be removed by freeing the skeletonized structure of the knife, allowing maximum lightness with minimum thickness. For lovers of extreme customization, the full-tang structure allows the neck to be covered with paracord cord. The sheath is composed of a very light and minimalist Kydex part. It can be disassembled and can be adapted to both left-handed and right-handed users. The addition of an optional belt clip allows both vertical and horizontal positioning of the knife and makes the sheath much more versatile than the textile version. It is equipped with a mini pouch with M.O.L.L.E. system containing a double-sided stone for sharpening and a Firesteel stone for lighting fires.