A connector and a teatcup that includes a connector and a cartridge. The cartridge includes a sleeve, having a first end and a second end, and a teatcup liner mounted in the sleeve and having an inner space for receiving a teat. The connector is configured to connect a milk conduit to the cartridge. The connector includes a casing, which defines a longitudinal center axis (x) and encloses a connection space. The casing has an inner surface facing the connection space. The casing includes an inlet opening for the cartridge to the connection space, and an outlet opening for the milk conduit. Locking parts are provided on the inner surface of the casing and configured to permit locking of the cartridge in the connector.