Switch contacts (electrical alarm contacts) make or break an electric control circuit dependent upon the position of the instrument pointer. The switch contacts are adjustable over the full extent of the scale range (see DIN 16085), and are mounted predominantly below the dial, though also partly on top of the dial. The instrument pointer (actual value pointer) moves freely across the entire scale range, independent of the setting. Both circular gauges and square panel-mounted gauges feature an adjustment key in the centre of the window. Contacts in flush panel-mounted gauges are adjustable using a screwdriver through the window. Several switch contacts can also be set to at the same setpoint. Contact actuation is made when the actual value pointer travels beyond or below the desired set value.