Closure member

Closure member (10, 110) for covering and/or closing a container (100, 200), in particular a bottle, the closure member (10, 110) comprising:

• a shell element (13, 113) comprising an opening (13d, 113d;
• 13d′, 113d′) provided in a top portion (13a, 113a) or a side portion (13b, 113b) of the shell element, the shell element (13, 113) being at least partially made of a conductive material, and
• a transponder (20, 120) comprising an antenna and being arranged in the closure member (10, 110) in or below the opening, the antenna being arranged at the opening (13d, 113d;
• 13d′, 113d′), wherein the antenna is arranged at the same level, or below or under the opening, and wherein the dimension of the antenna øAntenna, the dimension of the opening in the shell øHole, and the distance between the level of the opening and the antenna d obey the following relationship:
• øHole−øAntenna≥0.2d+2 mm for d≥0.64 mm (I.)
• øHole−øAntenna≥−4.96d−0.9 mm for t≤d<0.64 mm (I′.)
• with t being the thickness of the shell element (13, 113) at the opening.