<p>The kit (1) has housing cooperated with a fixation unit, where the housing is conformed for realizing a seat. A head of the fixation unit has a truncated shape lower face that is in contact with a support against a truncated shape face of the seat. The seat and a head of another fixation unit are cooperated with each other for permitting a variation of the orientation of the latter fixation unit with respect to an assembling part (2) e.g. ostesythesis surgical plate. Blocking units seal the head of the fixation units.</p>
