What you are looking at is the new ColorVision Monitor Spyder. What it does is calibrate any Macintosh or Windows monitor easily, with accuracy and efficiency. The best thing is that it is inexpensive and comes bundled with different software depending upon your needs. Now that you know what it is - you might want to know why you need a Spyder.
Monitors leave the factory in a wide variety of conditions.
If you're interested in matching screen colors to print, you need to insure that your monitor is calibrated. Software alone can not guarantee that. A calibrated monitor displays neutral gray from just below pure white to just above pure black. It displays white that is standardized to a Kelvin temperature of choice and a black point that is correctly set. If you think that you may not know how to use it.