A rotary joint or swivel device for ensuring a continuous connection between two items that rotates with respect to each other, for example between an instrumentation unit on a fixed installation and sensor elements in a cable on a rotating cable reel or drum, is provided. The rotary joint or swivel device comprises a minimum of two spools 1A,B to coil a connecting cable 3. A first spool 1A is coupled to a first, static, item 40. A second spool 1B is coupled to a second, rotatable, item 30. A guiding arm 4 feeds the connecting cable 3 from the first 1A to the second 1B spool. Correspondingly, a method for ensuring a continuous connection between two items 30,40 that rotates with respect to each other is provided. The method comprises arranging a rotary joint or swivel device according to any of the embodiments of the invention between the two items.