<p>A portion of the surface area of a resin bonded structure comprises an exposed dimpled electrically conductive metal shim bonded to the structure to provide a low electrical impedance connection for mounting a device such as a radio antenna. Preferably, a ply of unidirectional carbon fibres coated with an electrically conductive material such as a uniform and concentric coating of electroplated nickel is located between the shim and the outer carbon fibre layer of the structure with the fibre orientation of the ply of coated carbon fibres at 90 degrees to the carbon fibre layer. The invention also extends to a method of providing a low electrical impedance connection on to a pre-cured resin bonded carbon fibre structure and to a method of attaching a radio antenna on to such a structure.</p>
