A capsule assembly for an endograft introducer is disclosed. The assembly comprises: a capsule retriever having a plug portion and a tail portion, the plug portion having a lead-in surface, the tail portion having an elongate body extending proximally from the plug portion to an end stop feature receiver; a capsule tube having an end stop feature at a proximal end thereof and terminating in a distal end, the end stop feature and the end stop receiver arranged such that proximal movement of the capsule tube relative to the plug portion is limited; and a capsule cavity inside the capsule tube, a proximal end of a prosthesis being receivable in the cavity. The capsule tube is slidably movable with respect to the capsule retriever to a position in which the distal end of the capsule tube is adjacent to the lead-in surface of the plug portion.