A concentrate container for an extracorporeal blood treatment machine with a fluid inlet at a first end of the concentrate container and a fluid outlet at a second end of the concentrate container as well as at least one connector to hold a coupling fitting of a fluid conduit, wherein at least one connector is concave in shape and is positioned inside the container. A system for use with this concentrate container, in which the coupling fittings are convex in shape. A connection piece provides for disinfection of the system.
