Looks like a singlestack. Very slick looking. I've always wondered if there was such a modification available. Not enough commercial market I suppose but I reckon there are a lot of Mannlicher rifles that sit idle due to lack of clips.

They were originally a disposable item, w/ ammo often being issued in clips. I'm guessing the various mils that issued them collected them and reused them in training but in combat/service use, I suppose most just hit the ground and were lost like Garand clips which are, of course, Mannlicher clips themselves.