There have been six models to date; three additional models were announced on September 1, 2010, and will be available shortly. The PRS-500 (PRS standing for Portable Reader System) was made available in the United States in September 2006. On 1 November 2006, Readers went on display and for sale at Borders bookstores throughout the US. Borders had an exclusive contract for the Reader until the end of 2006. From April 2007, Sony Reader has been sold in the US by multiple merchants, including Fry's, Costco, Borders and Best Buy. The eBook Store from Sony is only available to U.S. or Canadian residents or to customers who purchased a U.S.-model reader with bundled eBook Store credit.
Reader Pocket Edition Known as the Pocket Edition, the PRS-300 was announced at the same time as the touch-screen PRS-600. It is meant to be the entry-level reader device, priced below the competition at US$150. It has a smaller screen than the PRS-600, no touch interface, no MP3 audio or expandable memory. It has a similar interface to the PRS-500 and PRS-505.
On November 16, 2009, Sony announced that a firmware update is available to owners of the original PRS-500. This update will allow your PRS-500 to support the ePub and Adobe DRM format and add the ability to re-flow PDF documents . Owners must send the reader in to the Sony Service Centers for the updated firmware.
Other new product features included auto-synchronization to a folder on a host PC, support for the USB Mass Storage Device profile, and full USB charging capability (the PRS-500 could only be recharged via USB if the battery was not fully drained, and if the Sony Connect Reader software was installed on the host PC). Also, adding books to Collections (a feature to organize and group book titles) is now possible on the storage card, unlike the PRS-500 model.