A rotatable connection for a mount device for placement in an operating room includes an adjustable stopping mechanism that can be disposed between a first connection component and a second connection component that is mounted rotatably relative to the first connection component about an axis of rotation. The adjustable stopping mechanism may be adapted to establish at least two different relative rotational angles of the connection components relative to one another or at least two different rotation ranges. The adjustable stopping mechanism includes a rotation lock that can be disposed non-rotatingly at the first connection component and a coupling part that can be disposed non-rotatingly at the second connection component and that has a form-locking contour for establishing individual rotational angle positions, and may include a stopping device with an integral stop. The stopping device may be non-rotatingly positionable. A support system or mount device are also provided.