Fortis continues the successful series of collaborations between Viper and Jesper Voxnaes. While possessing the unmistakable stylistic features of the Danish designer, this folding knife differs from Odin and Kyomi in the extremely small thickness. This feature makes it even more comfortable in the daily carry, without giving up being a handyman knife. This knife reaches the highest level of cutting skills because of the Böhler M390 Microclean steel, a third-generation powder metallurgy material.