A device used for ventilation includes a ventilation mask that can be connected to a respiratory gas hose. The ventilation mask has a respiratory gas hose coupling that is movably connected by a joint with the base of the ventilation mask. The joint is a ball-and-socket joint, which has an inner part that is shaped like a spherical segment and an outer shell for guiding the inner part. The outer shell is constructed from at least two shell segments that can be connected with each other.