A teatcup, a connector (2) and a cartridge (1) are disclosed. The teatcup is configured to be attached to the teat of an animal to be milked. The cartridge comprises an elongated sleeve (8), having an upper end section (8') and a lower end section (8"), and a barrel (9) pre-mounted in the elongated sleeve (8) and having an inner space (10) for receiving the teat. A pulsation chamber (11 ) is formed between the elongated sleeve and the barrel. A head member (12) provided at the upper end section comprises a lip (13) surrounding an opening (14) to the inner space. The elongated sleeve has a flange (20) extending outwardly at the upper end section. The head member comprises a plurality of locking members (19) each gripping the flange. Each of the locking members extends towards the lower end section and beyond the flange.
