It's an amazing training tool, and yes you can use it in pistols. You actually know when you get hit, and it makes you check your corners properly. For guys saying that airsoft is just as good if not better. . . if you can't get your hands on simunition then it's an acceptable substitute. Reball is also a good thing to use if you can't get your hands on sim. But you don't feel airsoft nearly as well as sim, not to mention having hundreds of rounds in a mag is unrealistic training (because most people wouldn't count out their rounds).
As for legalities that's already been covered. But it is a made in Canada product (at least the stuff I've used)