To install the T505 in your car, first slide metal visor clip onto T505, then secure T505 to the sun visor in your car as shown above. Tip: The visor clip attaches to your T505 in both directions. Slide the clip in the direction of the embossed arrow on the clip. While you may reverse the direction of the clip if you prefer, the Call Button should always be facing towards you. IMPORTANT: The T505 should not be left in the heat of an unattended vehicle for an extended period of time.