Which part?
When I say "toggle" I'm thinking of toggle bolts, and probably should say "two piece hinged" or something. It looks like the bolt carrier is two-piece, and the tail of the carrier is hinged, allowing the rear half to swing down and into the tube in the buttstock as the front part of the carrier and the bolt get shoved back. I have the feeling the whole thing is a shorter stroke than is allowed by a regular buffer tube.
As for getting my wife onto an AR-platform, she hates pistol grips. She claims they hurt to use. I don't see how that can be, and I kind of think it's either minor dislike of the ergonomics or major dislike of the aesthetics (the latter being very likely). Regardless, this would get her into something that's semi-auto, takes mags and ammo I've already got plenty of, and will work with most of the same parts as the AR spare parts kits I've got kicking around.