That look a lot like my Sig X 5 21 rounders.
Here is a link to the mag I gauged as slightly too long:
http://gregcotellc.com/cart/cz-facto...44-p-1706.html
Likes pretty much everything in every caliber.
That's not the OEM +2 base pad
This one is
https://hbindustries.net/store/shop/...ne-2-base-pad/