The Apple Hdmi To Dvi Adapter Allows You To Connect Your Mac With Built-In Hdmi To A Dvi Display Or Projector. You Can Use An External Display As Your Primary Display, Extend Your Desktop To A Second Display, Or Work In Mirroring Mode With A Projector So You Can View What Your Audience Sees. Use The Hdmi To Dvi Adapter To Connect A Single-Link Dvi Digital Monitor, Such As The 20 Inch Or 23 Inch Apple Cinema Display, That Includes A Dvi Connector. Review The Documentation Or Check With The Manufacturer Of Your Monitor To Make Sure You’Re Choosing The Right Adapter.