A connector includes a connecting body with a fluid passage at least part way therethrough, and a seal is provided with an outer portion of a fluid tube. A cartridge proximate to the connecting body has a hollow portion therethrough. A grab part has at least one tooth to retain the fluid tube and is between the cartridge and the seal. A demount part within the hollow portion moves the teeth to allow release of the fluid tube. A latch is located on one of the connecting body or a sleeve covering at least part of the cartridge or the connecting body. A mating catch is located on the other of the sleeve or the connecting body, and engagement of the latch with the catch connects the sleeve to the connecting body and helps restrain cartridge movement.