Retaining the 6" screen size, Amazon has updated its advanced E-Ink technology to further minimize glare and promote sunlight readability. Users can access the Kindle Store to browse and download books via Wi-Fi connectivity, with most titles accessible less than 60 seconds after purchase. Approximately 1400 eBooks can be stored within the device due to an internal storage capacity of 2 gigabytes, with additional online storage provided to users via Amazon's Cloud service. A full battery charge can last for up to one month with wireless turned off, enabling long-term mobile support for uninterrupted reading. Users who own another Kindle product or device with the Kindle application can synchronize bookmarks and annotations between interfaces via WhisperSync, making it easy to switch between smartphone and tablet devices throughout the day. The Kindle is available with or without "Special Offer" advertising at a $30 price differential.