Book Nook (adjustable size)

When I have a gap on my shelves it always bugs me that my books lean over and could get damaged.I have tried bookends and other assorted things but nothing really does what I need.So I sketched out a few ideas and went through an iterative process of model, print, edit, print again until I was satisfied.What I ended up with it an adjustable solution that is only two pieces. It has no rigid locks and works solely on friction fit.