Schematic representation of the customizable tether design used in zebra finch in vivo microdialysis. At the top is the swivel connected to the microdialysis cage with inlet and outlet FEP tubing. The top of the tether (lever arm) contains either a thin wire or plastic straw (such as those that are shipped with CMA 7 probes to protect them) to enable lightweight rigidity, and it is then enshrouded with tape. The tether is angled to provide a lever arm to translate rotational torque from the bird to the swivel while also allowing full freedom of movement (including flight) inside the cage. Multiple tape component stages ensure flexibility in addition to an angled lever arm.