Elastic sleeve ring for sleeving timepiece movement and watch case comprising such elastic sleeve ring

One aspect of the invention relates to an elastic sleeve ring (200) for sleeving a timepiece movement (10) inside a watch case (100), said watch case comprising a central piece (110), said elastic sleeve ring (200) being characterized in that it comprises an annular body (205) having a central axis (Z), and a fastening tab (210) carried by said annular body (205), said fastening tab (210) comprising a fastening element (210) for fastening said fastening tab (210) to said central piece (110). The elastic sleeve ring (200) comprises at least one elastic retaining element, and can cooperate with the central piece (110) to form a bayonet sleeve system (300) by rotation of the elastic sleeve ring (200) relative to the central piece (110) about the central axis (Z) between an insertion position and a locking position, the elastic sleeve ring (200) comprising at least one elastic retaining element, the elastic sleeve ring (200) is provided with at least one elastic retaining element which can cooperate with the time