The invention relates to a lockable joint, especially a lockable ball-and-socket joint, comprising a first arm (14) having a swivel head (30), a socket (32), the swivel head (30) being pivotably mounted to the socket (32), and a locking device (90) arranged for locking the swivel head (30) with respect to the socket (32), the locking device (90) having a piston (70'), a pressure gas source (64), and an actuating device (92) arranged for reversibly disconnecting the piston (70') from the pressure gas source (64) where in the pressure gas source is a gas cartridge (64).
