Abstract: A watch case includes a middle having a first opening receiving a crystal, opposite a second opening receiving a back. The back is held such that it bears against an annular bearing surface of the middle by a threaded ring cooperating, by screwing, with the middle. The back includes a first indexing element to cooperate with a second indexing element with which the middle is provided so as to immobilise the back in a single angular position such that it cannot rotate relative to the middle.

Abstract: A device (1) for fastening a bracelet (2) to a watch case (3), at two pairs of horns (4), by a female connecting element (5) secured to the case (3) of the watch and a male element (6) secured to one end (20, 21) of the bracelet, these elements being complementary cooperate by fitting one into the other, while forming removable assembly capable of making the bracelet interchangeable. The male element includes a rod (7) connected to an end (20, 21) of the bracelet, and extending on either side of the rod, a ball-pawl (8) and first (70) and second (80) cylindrical shouldered portions arranged concentrically around each ball-pawl, each ball-pawl and each cylindrical shouldered portion being arranged to cooperate respectively with blind housing (50) and groove (51) proximate to the blind housing, and forming the female connecting elements on inner areas of the two pairs of horns.

Abstract: A watch case includes a middle having a first opening receiving a crystal, opposite a second opening receiving a back. The back is held such that it bears against an annular bearing surface of the middle by a threaded ring cooperating, by screwing, with the middle. The back includes a first indexing element to cooperate with a second indexing element with which the middle is provided so as to immobilise the back in a single angular position such that it cannot rotate relative to the middle.