Certain examples of the present invention relate to a multi-electrode device for use with a user's body part. Certain examples provide an apparatus (100) comprising: a plurality of electrodes (101); a signal line (102) for conveying electrical signals to or from the plurality of electrodes (101); wherein the plurality of electrodes (101) and the signal line (102) are integrally formed in the apparatus (100), and wherein the apparatus (100) is configured such that a user is able to selectively electrically couple one or more of the plurality of electrodes (101) to the signal line (102).