As mentioned, the 40P is this slide
(originally sold as the Colt Z40)
on this frame
...and this is mine.
Mine has been flawless after a 200 round break-in. It has had a Wolff extra power recoil spring, extra power extractor spring, reduced power mainspring, and a full length guide rod installed. It's a tremendous bargain, although QC seems varied, and they all seem to be a bit undersprung.