They are not striker fired.
They look like it but have an internal/hidden hammer.
When you pull the slide off you can see the hammer down in the frame at the back. That's how they get by with the lighter recoil spring. Cocking the hammer takes some of the force from the slide as it moves rearward. They came out with the .380 first (piss ant recoiling little cartridge), then the 9MM. They've recently released a new model called the Equalizer that uses the same design. Nothing in the name that leads you to believe there's any "EZ" there but it's the same. Another funny thing about it is there is no M&P on the box or the pistol. Just S&W. The slide gripping surfaces are different (wide and vertical vs. the usual M&P scalloped look) and the grip surface is different (rough all over but more so in places and still different than the previous models.
Only thing it has in common with the M&P pistols is using the same mags. the Shield Plus uses with the addition of a 15 round magazines in states that don't limit magazine capacity. The Shields come with two mags. The Equalizer comes with three (10, 13 and 15). It also comes with a maglula magazine loader in the box.
Pay no attention to the Mantis on the front rail. My wife is trying to get used to the (not as good as a Shield) trigger. It's a SA semi auto with more drag/bumps/catchiness than her Shield 9MM. Oh, the optics cut accomodates the Holoson with no modifications required. Again, different than the Shields.