We already suspected the Galaxy S III would make its way to T-Mobile, but now we’re 99 percent certain thanks to the loose-lipped FCC. (When the device will hit is an entirely different matter.) According to a recent filing uncovered by Engadget, a Samsung handset sporting the model number SGH-T999 (the Galaxy S II was T989) has made a quick stop at the agency touting 1700MHz AWS support — a sure indicator it’s headed to T-Mobile. In addition, the T999 looks to have support for 850MHz and 1900MHz WCDMA bands being used for HSPA+, Engadget said, making the device a prime candidate for T-Mobile’s planned expanded network. So we know it’s coming; the S III’s presence at the FCC perfectly sets the device up for its anticipated summer launch.