Allowing mirror to be removed without damaging or removing the mirror assembly.

Applications:
1997-2002 Windstar
1998-2004 Crown Vic, Grand Marq, Marauder, Taurus, Sable, Mustang, TownCar
1999-2004 Ranger, Excursion, Super Crew (F-250--F-550), F-650, F-750
2001-2004 Escape
2002-2004 Thunderbird
1996-2004 Explorer
1997-2004 Mountaineer
1998-2004 Expedition, Navigator, F-150
1999-2004 E-Series van
2000-2004 LS
2001-2004 Explorer Sport, Explorer Sport Trac
2003-2004 Aviator
1999-2004 Dual arm mirror used on Excursion, Super Crew (F-250--F-550),F-650, F-750
1999 and newer Ford interior / rearview mirrors that have the detachable (screwless) mount.