Method and apparatus for overmolding delicate parts are disclosed. The jewelry assembly is constructed such that it remains centered when worn and such that it can be adapted to fit individuals of different size. The annular section directly adjoins the flange, and the annular section and the flange form a head section which has a uniform outside diameter throughout, and wherein the polygonal shape of the flange extends over the annular section up to its front annular surface. Feedback is provided to control the rotation of the flywheel. Accordingly, it may be possible to implement the user interface which is conveniently and easily controlled. In the pressure sensor, the gel member is exposed from an opening portion of the element locating portion in the casing such that the pressure of the pressure medium is applied to the pressure detection element through the gel material, and the gel member protrudes from a surface of a circumference portion of the opening portion in the casing.