Examples disclosed herein relate to conduits, devices, systems and methods, which may include a hollow element including an inner surface and an outer surface which allows for a passage of one or more of one or more fluid elements and one or more gaseous elements, a constraining element with one or more openings and one or more non-open elements, one or more blocking elements configured to stop the passage of the at least one of the one or more fluid elements and the one or more gaseous elements when the one or more blocking elements are in a first position relative to the one or more openings, and a movement device configured to move the one or more blocking elements to a second position relative to the one or more openings which allows for the passage of the one or more fluid elements and the one gaseous elements through the one or more openings in the constraining element.