Abstract: A heat-transferring fin is attached to an electric cable or to a packaged double cable of an electric radiant heating system. The fins can be attached using twist clips. Each twist clip includes an upper gripping member, a lower gripping member connected to the upper member by an upright support member, and a handle portion looping downwardly from the lower gripping member to enable a user to hold the clip and to manually twist the clip to cause the upper and lower gripping members to rotate relative to the fin and cable such that the fin and cable are clipped together. This twist clip enables quick and easy attachment of fins to cables, which greatly reduces the time and effort required to install an electric radiant heating system. This technology can be used in electric radiant floor heating or electric radiant wall heating.