A book stand that won't fall over even with just one book

When you insert a book or something from the front, the stopper rises.
Stoppers on both sides hold the inserted items in place so they won't fall over.

When you remove one of several books, the stopper for the removed book will drop.
The design makes it difficult for adjacent books to fall over, and it's easy to see where to put them back!

In addition to books, it can also be used to organize CDs, DVDs, etc.
Can be connected using joints on both sides.
The back side has anti-slip rubber feet.