The Galaxy S III is a flagship smartphone from Samsung company. Same as Galaxy S II, the Galaxy S III has different versions in USA market. The Samsung’s standard model for Galaxy S III is GT-I9300. But each telecommunication company in USA has different model number. Verizon calls it Samung SCH-I535, U.S. Cellular calls it SCH-R530, Sprint calls it SPH-L710, AT&T calls it SGH-I747 and T-Mobile calls it SGH-T999. Though they have different names, all use same Android™ 4.0, Ice Cream Sandwich operating system.