Mating the Sansa Car Transmitter to the FM radio:

Step One: Tune the car radio to an unused or weak FM frequency, which often can be found at each end of the dial.

Step Two: Locate the same frequency on the Car Transmitter by using the channel search buttons, and then press play. (Up to three presets can be programmed with the memory buttons, and frequencies can be viewed on the blue backlit LCD screen.)

Whats in the Box?
Transmitter ,durable transparent belt clip, which is necessary for inserting the player into the transmitter cradle, and rubber gaskets to establish a snug fit in the 12-volt lighter socket.

The transmitter covers the full FM band, from 88.1 to 107.9 megahertz (MHz), so a user can select any weak frequency.

The transmitter is part of a new accessory line for the Sansa e100 series of MP3/WMA players. SanDisk introduced the players, which come with embedded memory of 512 megabytes (MB) or 1GB, last spring. With the player's built-in SD card slot, users can add as much as 2GB of supplemental memory, giving the 1GB Sansa (model e140) a capacity of 3GB. And by using the Windows Media Audio (WMA) compression format, that expanded memory can store up to 96 hours of music, or the content of approximately 100 CDs(1).