Quick-release cap with ejection ramp

A quick-release cap is provided for closing the neck of a housing. The cap includes a core having a first end, a second end, and an exterior side wall between the first and second ends. The cap is configured to rotate between a cap-locked position securing the core within the neck and a cap-release position permitting removal of the core from the neck. A first groove is defined in the exterior side wall of the core and extends at least partially circumferentially around the core for receiving a first tab protruding from the neck. The first groove defines an ejection ramp for at least partially ejecting the first tab relative to the first groove when the cap moves from the cap-locked position to the cap-release position. The cap may be removed from the neck with the application of only a twisting force.