The listing, Mini DisplayPort to DVI Adapter--BNIP has ended.
The Mini DisplayPort to DVI Adapter lets you connect an advanced digital monitor, such as the 20- or 23-inch Apple Cinema Display, to a Mac with a Mini DisplayPort.
Overview
Every Mac with a Mini DisplayPort allows you to connect an external display or projector using an adapter. You can use an external display as your main workspace or to extend your desktop, or you can work in mirrored mode with a projector so you can view what your audience sees.
Use the Mini DisplayPort to DVI Adapter to connect an advanced digital monitor, such as the 20- 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.
Compatible only with Mac computers with Mini DisplayPort.
For more info, you can look it up on the Apple site--
http://store.apple.com/us/product/MB570Z/A#overview
Retails for $29
Brand New in Package.
My son bought it for my daughter for Christmas thinking it was a plug for her iPod.