Not sure if I'll get it now, but at only about $90. this is a great deal!! It's (almost) a 4pt harness and seems much safer than any others I've seen. (The difference, from what I can tell is that the belts don't criss cross over the child, but rather just the seatbelt...)
BTW, it seems like some other seats might be able to be converted (Britax seats) but not sure. Perhaps someone can comment...
Britax Booster