mixing of two products includes two bottles separated by a connector bearing a removable stopper the connector means includes two separate parts a first part bearing the top of a central hollow shaft supporting the stopper which can be screwed in leaktight fashion onto the base of the first bottle a second part fitted onto the first bottle which forms a bottom of the central hollow shaft bearing means which assist in expelling the stopper so that the products can be mixed and an anti rotation device for preventing the second part from rotating with respect to the first application_number US 7298198 A description reference to the drawings especially to fig1 to 4a 4b reveals a packaging c with two bottles 1 2 which allows two products generally two liquid products to be stored separately from one another and to be mixed at the time of their use the first bottle 1 is intended to contain a first liquid product for example an oxidizing agent intended to be mixed at the time of use with an oxidation colorant contained in the second bottle in order to dye hair the bottle 1 is open at its base wherein the base comprises a cylindrical skirt 3 of circular cross section the skirt 3 connects to the wall of the main part of the bottle 1 by a shoulder 4 teeth 50 are arranged uniformly around the periphery of the shoulder 4 and as will be seen in more detail later constitute means for locking a part 80 of a connecting means 8 onto the bottle.