Abstract: A back (1) for a watch case (50), the back (1) including a first element (10) arranged so as to be screwed onto the watch case (50), and a second element (20) including an end face bearing a pattern (M), the second element (20) being mounted such that it can move in rotation about an axis (C) passing through the centre of the case (50), wherein the second element (20) has a brake arranged so as to hold same relative to the first element (10) in different angular positions about the rotational axis (C), the brake being disposed between the first and second elements (10, 20).

Abstract: A back (1) for a watch case (50), the back (1) including a first element (10) arranged so as to be screwed onto the watch case (50), and a second element (20) including an end face bearing a pattern (M), the second element (20) being mounted such that it can move in rotation about an axis (C) passing through the centre of the case (50), wherein the second element (20) has a brake arranged so as to hold same relative to the first element (10) in different angular positions about the rotational axis (C), the brake being disposed between the first and second elements (10, 20).

Abstract: Clasp for a piece of jewellery or wristwatch, including a stretcher like structure with a first housing in which a first push-piece and a second push-piece are moveable on a first bearing surface against an elastic return means, and held by at least one closure plate able to occupy a closure position in a second housing. The clasp includes at least one resilient locking element for this closure plate, including a push-button, held in this stretcher like structure and arranged, in a compressed position, to permit the motion of the closure plate and, in a relaxed position, to immobilise this closure plate in the closure position via the cooperation of this push-button with a fourth housing comprised in the closure plate.