Here's the the S&W website page for it.

I was originally trying to buy an Airlite 340 PD with the titanium frame and scandium cylinder (11.3 oz), but those are a little bit pricier and harder to find. This one was priced right and has a stainless cylinder with titanium frame. So at 13.3 oz, it still weighs a little less than a 642 (15 oz). Mine has the Uncle Mike type boot grips instead of the Hogue grip that is pictured. I'll probably swap that out later for the Hogue. And unlike the 340 PD Airlite, this gun has a large white dot front site from Trijicon with a tritium insert. The sight channel and rear notch in the top strap has been cut more deeply than the 640 or 642 sights and registered to fit the front sight very well. It actually presents a very serviceable sight picture - much better than on my other snubbies. This pistol has a trigger lock and a lanyard loop in the bottom of the grip frame. The ejector shroud is full length under the 1-7/8" inch barrel.
The entire gun is coated in a matte black finish. There is a white outlined "M&P" logo on the ride side of the frame with "SFLD,MA" and "S&W U.S.A." engraved into that side, and a white circular "S&W" logo on the left side of the frame with "Military" and "Police" banners at the top and bottom of the circle. The left side of the barrel has white lettering with "SMITH & WESSON" on it, and the right side of the barrel has ".357 S&W MAG" engraved into it.
I also bought a 25 round box of 125 grain Hornady Critical Defense .357 ammunition for carry use, based on the Camp's Corner review of the same in .380 and .38 Special.
Pictures will be forthcoming, and I'll post an after action report after my first range trip. Anyway, I'm tickled pink. I traded away my 642 for that 640 of mine. I really like the 640, and I'll keep it, but it weighs just a bit too much for really comfortable pocket carry; and while I do enjoy this gun, I've since come to regret getting rid of my 642. That said, I get a kick in the pants out of the .357 cartridge, and as long as I'm going to lose velocity and power to a short barrel, I think I'd rather have the .357 than the .38. And if it is just too much to handle, I can always still step down to +P .38 Special. But I'm a reasonably experienced shooter, and I'm used to .44 magnum power, so the .357 isn't particularly intimidating to me. And even if stings my hand to shoot it, I don't think that's actually going to be much of a factor in a real shooting situation.
edited to correct a misspelling: "mat" to "matte"