An applying unit for applying lids (100) of opening devices (2) to spouts (4) of packages (3) comprises a plurality of applying devices (40) arranged for applying said lids (100) to said spouts (4), a plurality of transfer arrangements (19), each transfer arrangement (19) supporting a corresponding applying devices (40) and being movable along a track arrangement (20), wherein said transfer arrangements (19) are self-movable along said track arrangement (20) and are movable independently from each other along said track arrangement (20).