Hi loknload,
It's a 9mm, works very well, and has around 2500 rounds on a Sprinco unit. The factory recoil guide is captive, so changing that spring would be a challenge. this one also has 1500 to 2000 rounds on it. No problems, but i normally change springs every 2000 to 2500 rounds.
It is the frame mounted safety version, so can be carried cocked and locked, and has an excellent trigger as DA auto's go. Very picky about ammo for accuracy, will feed most anything.
Only negative is that it is heavy for the caliber, whcih also means it is very controlable, even with +P's.