The unit is assembled of the curved tube (1) fitted with an inner tube, and a holding plate (2) attached to the outer surface of the neck of the patient. The plate (2) is joined to the tube (1) with a ball and socket joint, facilitating the plate (2) to be moved in a complete circle and in several other directions in order to adjust its position to the neck shape of the particular patient and to move in coordination with the patient's moves.
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