Abstract: In embodiments, a base cord, comprises: an insulating cord body with a first and second ends; a plurality of conducting wires running within the cord body from the first end to the second end; a female terminal comprising a plurality of different sets of conducting holes, with each respective different set of conducting holes connected to a different set of the conducting wires, and adapted for connection to an associated male terminal head with male conducting posts that fit within the conducting holes of the respective set, wherein a first one of the sets of conducting holes has at least one different shape compared to shapes of a second one of the sets of conducting holes. In embodiments, a kit may comprise the base cord and one or more interchangeable heads.