A foldable mobile phone hardset includes a first part and a second part which are pivotably connected by an elastic sheet. The sheet has a first end fixed in a curved slot in the first part and a second end fixed in a curved slot in the second part. The curvature of the sheet adds to the spring loading of the parts toward a stable open position of the phone, wherein the sheet has a uniform curvature along its length. The electronic components of the two parts are connected by an electronic element which is laid against the elastic sheet, the electronic element and the sheet being encased in an elastomeric sheath.