The main supporting element is a hook, which is made of a special aluminium alloy. After several heat treatments, it has parameters that guarantee maximum safety for the user. These parameters were tested in the laboratory of the Faculty of Mechanical Engineering of the Czech Technical University in Prague and the result was the finding that the hook can withstand 650 kg without significant deformation. At higher loads, irreversible deformation occurred, but not cracking.
The second supporting element is three types of gaffs. All are cast from alloy steel (Cr, Ni, Mo). After thread cutting and subsequent heat treatment, when the gaffs are tempered to a value of 1000-1200 MPa, they are screwed to the hook with a pair of M8 screws. These screws are tightened to a value of 25N / m and a layer of glue is applied to them, which prevents their spontaneous loosening. The gaffs are shaped so that they allow the leather or synthetic strap to be pulled through the gap, which ensures the stability of the foot in the area of the ankle. Due to the perpendicular to the base, the grinding angle is 30 °. The gaffs were also tested in the above-mentioned laboratory and up to 650 kg there is no significant deformation or breakage. At higher values up to 1000 kg, the tip of the spike is permanently deformed but does not break.
The third element is the shell. It is made of several layers of glass fabric and reinforced with a strip of carbon fabric. The holes in it allow this support to be moved according to the user´s needs. The shell is attached to the hook with a pair of M6 screws. The calf support, pad, is attached to this shell with the help of Velcro. This is shaped longitudinally to provide maximum comfort to the user.
The leg is attached to the hook with either textile stripes with Velcro or synthetic strap.
