The disclosed technology includes basket catheters comprising a generally cylindrical structure having electrodes attached thereto. The disclosed technology can include a one-piece flex circuit comprising a proximal end and extending along a longitudinal axis to a distal end. The proximal end diverges into a plurality of first arms, each of the first arms divides into second and third arms that are connected to respective fourth arms proximate the distal end to define an elongated shape disposed about the longitudinal axis. The disclosed technology can include a structural unit for an end effector having a proximal hub, a distal hub, and a plurality of spines forming a generally cylindrical structure. The spines can comprise a plurality of first members attached to the proximal hub that diverge into a plurality of second and third members connected to respective fourth members proximate the distal hub.