Abstract: A device for keeping ready passenger oxygen masks is disclosed. In embodiments, the device comprises an oxygen connection and a module container which can be fastened onto or installed in a passenger service unit (PSU) and includes compartments for receiving passenger oxygen masks, said passenger oxygen masks being connectable to the oxygen connection and being arranged ready for use. The module container comprises a release opening with an opening edge, and a cover which closes the release opening. The cover is releasably fastened to the opening edge and comprises a pull flag for removing the cover from the opening edge, wherein the cover and/or the pull flag is connected to an activation unit for activating an oxygen flow from the oxygen connection to the respective passenger oxygen mask.