And if you buy their X-change kits you can change from full size to sub compact, etc. Kit includes barrel, slide, spring & grip & you just remove the FCU (Fire Control Unit / I.e. Trigger Assembly), from the full size caliber & insert it into the smaller (sub compact) grip, along with the sub compact slide assembly from the X-change kit for that same caliber. Like Killerford indicates, 5 minutes & you have a different sized firearm. I got the 9, 40, 357, & 45, in all different kinds of configuration possibilities with different grips & X-change kits.