Learning Resources 2-Color Desktop Abacus, Red Frame, Color Coded, Math Concepts

What are the frame and beads made of? Are they durable? I have a toddler who will probably get her hands on this when older sister is using it.

what is the purpose of the double columns and the empty columns?

I can see there are 2 columns (20 beads) marked [1], [10], etc. Why? Shouldn't there be only 10 beads for each column (ones, tens, hundreds, etc)?

Manufactured where?