An improved adjustable rotary locking and unlocking device that utilizes a pushbutton to unlock teeth on a spring loaded hub drive that mesh within a swivel member. Once the hub drive and swivel member are disengaged by pressure on the pushbutton, the swivel member is freely moveable to any other position. Release of pressure on the pushbutton allows the teeth of the spring loaded hub to re-engage the teeth of the swivel member, thereby rigidly locking the device in place.