The stopper (3) is opened by a half 360 degree rotation for unlocking and therefore whereas the opening operation is not interrupted, allowing direct and secure contact with the users hand. Two or more outwardly formed parts (8) of the stopper can grip laterally over the bottle mouth and therefore a greater effective length is provided for more secure gripped bottle a users hand can operate. The closure can have a section which fits into the mouth of the bottle for a secure sealing and an improved noise when opened. The stopper can have projections (5) which fit into recesses in the bottle neck.
