The invention relates to a cartridge system for mixing and applying two fluids, in particular of a medical cement, comprising two cartridges and a discharge opening, wherein the cartridges are delimited by cartridge walls and by a cartridge head, wherein at least one cartridge opening for expelling the cartridge contents from both cartridges is provided in each case in the cartridge head, wherein a device for regulating the streams of fluid from the cartridges is arranged on the cartridge head, said device comprising at least two wings and at least two openings, which at least in some areas cover at least two cartridge openings, wherein the device is arranged rotatably or slideably on the cartridge head, wherein on at least two openings at least one wing is in each case arranged which at least in some areas protrudes past the opening, such that a flow through the openings applies to the device, via the wings, a force parallel to the surface of the openings, which force leads to a sliding or turning of the device against the cartridge head, in which the surface of the cartridge openings covered by the device changes, and such that a housing comprising the discharge opening is arranged on the cartridge head, in which housing the device is arranged so as to rotate or slide. The invention also relates to a device for such a cartridge system according to the invention, which device can be arranged rotatably or slideably on a cartridge head of a cartridge system, to a method for synchronizing streams of fluid with a cartridge system according to the invention or with a device according to the invention for a cartridge system according to the invention, and to a method for mixing a mixable material using a cartridge system according to the invention.
