A connection system between a head and a bottle of a trigger dispensing device includes a main skirt having a first flexible tab and a neck having a first sloping plane and a first pocket. The first flexible tab extends circumferentially from a first end to a second end, and the first end is joined to an annular wall by a closing wall. The system also provides for an auxiliary window obtained through the annular wall of the main skirt, and a rigid auxiliary tooth of the neck, suitable to snap into the auxiliary window.