Bottle Cap

A bottle comprising:

• a reservoir including a neck and a plurality of protrusions formed on an outer surface of the neck, each protrusion having a horizontally projecting latch, an inclined surface formed on a bottom of an end of the latch, and a recess formed between the inclined surface and the protrusion;
• a cap including an inner top wall, an internal annular wall, and a plurality of projections formed on an inner surface of the annular wall, each projection being parallelepiped and having an engagement surface on a top, the engagement surfaces being flush;
• and
• a disc shaped sealing member including an annular raised edge, and a plurality of flexible elements formed on a top, each flexible element being upward inclined toward a center and having an open end wherein the sealing member is disposed in the cap to engage the open ends of the flexible elements with the top wall and rest the raised edge on the engagement surfaces of the projections;
• wherein in response to putting the cap on the neck and clockwise rotating the cap, the projections ride along the inclined surfaces to be locked in the recesses, the open ends of the flexible elements urge against the top wall, and the sealing member is airtightly disposed on the neck.