A wristworn device comprising a radio communication device for receiving from and/or transmitting signals to a radio communication device external to the wristworn device. In at least one embodiment, the casing comprises a metallic watchcase having a slot, and wherein the watchcase is electrically coupled to the radio communication device to function as the antenna. In another embodiment, a metallic loop is provided in the casing proximate the watchcase, wherein the metallic loop is electrically coupled to the radio communication device to function as the antenna and the watchcase comprises a slot and functions as an element for the reception and/or transmission of electromagnetic radiation. In a third embodiment, the metallic watchcase does not have a slot and the watchcase is electrically coupled to the radio communication device to function as the antenna.