I wrote a review for this abacus, but for some reason it didn't save so instead you'll be getting an inferior review. It shouldn't matter though because this is an inferior abacus.
I tried to input a single number into this abacus and simply couldn't.
On the positive side, it's quite sturdy as it's built entirely of iron or steel. You're more likely to injure yourself sitting on it than bending this thing.
It sucks. I hate it. No self-respecting abacus enthusiast should own this. It's a good thing I have no respect for myself. Get a Soroban or Suanpan instead.