A developer cartridge holds developer that is supplied into a print process cartridge of an image forming apparatus. The wireless terminal is initially part of an existing centralized network that includes an access point able to control the association of wireless terminals to its network. The at least one vortex generator extends partially into the passageway. This can provide the result that when the external connecting terminals 8 are connected to the external terminals 23, the connection can be performed while confirming the placement of the solder balls 21 from the respective through holes.