An apparatus (300, 800) comprising: a first member (310,830) with a first surface (311, 831), the first member comprising a first magnet (314, 834A) configured to generate a first magnetic field (315, 835A); and a second member (320, 820) with a second surface (321, 821), wherein the first member is movable relative to the second member, the second member comprising: a sensor (326, 826B) operatively connected to a processor, the sensor being a Hall sensor and is configured to only detect magnetic fields that run perpendicular to the second surface of the second member; and a second magnet (324, 824B) adjacent and oriented relative to the sensor, and is arranged to generate a second magnetic field (325, 825B) that runs parallel to the second surface of the second member to be undetectable by the sensor, wherein in a first position, the first magnet and the second magnet are engaged to magnetically hold the first member to the second member such that at least a portion of the first surface of the first member opposes at least a portion of the second surface of the second member, and the first magnetic field generated by the first magnet is arranged to run perpendicular to the second surface of the second member; and wherein the sensor is positioned intermediate the first magnet and the second magnet in the first position, and is configured to detect the first magnetic field and to further send a signal to the processor, in response to detecting the first magnetic field. a first member (310,830) with a first surface (311, 831), the first member comprising a first magnet (314, 834A) configured to generate a first magnetic field (315, 835A); and a second member (320, 820) with a second surface (321, 821), wherein the first member is movable relative to the second member, the second member comprising: a sensor (326, 826B) operatively connected to a processor, the sensor being a Hall sensor and is configured to only detect magnetic fields that run perpendicular to the second surface of the second member; and a second magnet (324, 824B) adjacent and oriented relative to the sensor, and is arranged to generate a second magnetic field (325, 825B) that runs parallel to the second surface of the second member to be undetectable by the sensor, a sensor (326, 826B) operatively connected to a processor, the sensor being a Hall sensor and is configured to only detect magnetic fields that run perpendicular to the second surface of the second member; and a second magnet (324, 824B) adjacent and oriented relative to the sensor, and is arranged to generate a second magnetic field (325, 825B) that runs parallel to the second surface of the second member to be undetectable by the sensor, wherein in a first position, the first magnet and the second magnet are engaged to magnetically hold the first member to the second member such that at least a portion of the first surface of the first member opposes at least a portion of the second surface of the second member, and the first magnetic field generated by the first magnet is arranged to run perpendicular to the second surface of the second member; and wherein the sensor is positioned intermediate the first magnet and the second magnet in the first position, and is configured to detect the first magnetic field and to further send a signal to the processor, in response to detecting the first magnetic field.