I know there is always exceptions but all the Sig OEM double stack factory mags I have seen has Sig Sauer and the caliber stamped on them, 9mm .40/357 357. Any clue as to what these mags might be and the capacity? Possibilities 226/228/229. Preban?

How about a couple of pics or more (both side plus the back)? But, one thing is for sure. If the back of the mag has the dovetail or the zipper appearance, that's factory German SIG.