Like the Trigger Jerk says, almost an upgraded version of the SR9 (no gaudy loaded chamber indicator or adjustable sights, etc) for a good chunk of change less ($100 less to be precise.) The frame looks just about identical, and it would make sense to use the same magazines. Mostly just some changes to the slide machining process to save some time and money. Smart move on Ruger's part I think, should make for a great entry wonder-nine.