The sub-assembly of external parts for a timepiece or watch or piece of jewellery, comprising a first component and a second component, which are provided for a bayonet fit between two edges and two wings which skirts of this first component and of this second component comprise, and are able to occupy an assembled and indexed position of the first and second components, the first component or the second component comprising for this purpose, in part in the thickness of the first skirt or second skirt, an elastically deformable zone comprising a lug for angular indexation between the first component and second component, cooperating with an indexation limit stop of the other component.

An interchangeable jewelry setting system that allows for the insertion, removal and replacement of ornamental elements onto a jewelry piece is provided. The jewelry piece may comprise any type of or piece of jewelry onto which an ornamental setting may be fitted such as, for example, a ring, necklace, earring, bracelet, broach, pin, etc. Likewise, any ornamental element may be disposed on the interchangeable setting of the invention, such as, for example, a metallic engraving, ornamental design element, etc.

A ring assembly comprising an outer ring body and inner ring body movably mounted thereto. The outer ring body comprises outer and inner wall and opposite face rim walls circumscribing respective openings. The inner ring body comprises outer and inner walls and opposite face rim walls circumscribing respective openings. The outer wall of the inner ring body is movably mounted to the inner wall of the outer ring body. The inner ring body is movable between a first position and a second position relative to the inner wall of the outer ring body. When the inner ring body is in the second position a greater portion of the outer wall of the inner ring body protrudes outwardly relative to one of the rim walls of the outer ring body.