The device consists of two vertebral plates (upper and lower), two rods and eight set screws four for each plate to fix the rods in its passage in the plates).each plates contain 2 holes for the vertebral screws. By the end of screw tightening, the head of the screw is flush with the vertebral plate. The design of the screw (the pitch of the mechanical thread of the head being half of the cancellous part of the screw) allows for compressing the plate into the vertebra. The design of the 2 rods provides a stronggripe of the set screws over the rods in the plate.