An indicator tool 304 for use with an implanted valve unit having a plurality of performance settings. The tool comprises a housing with a readout window 344 and an indicator wheel assembly 359 capable of rotating within the housing on a spindle rotatably supported by the housing, and carrying indicia of performance settings sequentially viewable through the readout window. The tool also comprises at least one magnet 360, 362 carried by the indicator wheel assembly to detect an actual setting of the implanted valve unit and a release mechanism 332 which, when actuated by a user from a first position to a second position, enables the indicator wheel to rotate as the magnet is drawn toward the actual setting of the implanted valve unit using a a complementary system of a first gear 330 and at least one catch 327, 329.
