The LG Optimus One is an entry-level series of touch-screen smartphones manufactured by LG Electronics, Inc. It was released running the Android 2.2 Froyo, and later LG released software to upgrade it to Android 2.3 Gingerbread. Although the basic physical form factor of each variant is the same, the variants have differences in hard button shape and layout, the form of the metal side bezel and the user interfaces added by LG or various carriers. Versions of the Optimus One exist that operate on various frequency bands and either GSM or CDMA-based network protocols. They may also feature one or more variations in hardware, such as a faster processor, the addition of a physical keyboard, a modem with higher theoretical speeds, or a better digital camera. Since sales first began in mid-November 2010, LG has released ten variants, though some differ very little from others. The Optimus One line is the first LG smartphone line to sell more than 1 million units. more than 2 million units have been sold worldwide, with 1.3 million units sold in North America, 450,000 units sold in South Korea, 200,000 units sold in Europe and 50,000 units sold in Asia and the CIS. Variants Because of the different technologies used by wireless operators in the United States, many variants of the LG Optimus One exist, usually replacing the word "One" with a single letter representing the carrier. For example, the LG Optimus M was offered exclusively by MetroPCS, while the LG Optimus T was only available at T-Mobile USA. Primary configuration The Optimus One P500 was the first version offered for sale, with sales beginning in South Korea in mid-November 2010. This GSM version of the phone is sold by wireless communications service providers in Asia, Europe and Canada. In Canada, the LG Optimus One (P500h) is sold by Telus Mobility since December 2010 and its brand Koodo Mobile since February 2011, with UMTS frequency at 850, 1900, and 2100 MHz. In Turkey, a matte black variant is sold as the LG Optimus One (P503). Walmart Family Mobile released the LG Optimus One (P504) in charcoal in September 2011. Carrier variants LG Optimus S: The LG Optimus S was initially released by Sprint in charcoal gray and purple on October 31, 2010. It includes the Sprint ID graphical user interface (GUI) and CDMA network connectivity. While it is similar to the Optimus One, the