This is a spool shelf designed to be installed on the IKEA Bror Trolley. It uses the extra hole where a Bror shelf could be placed for the top layer, and requires drilling extra holes for the bottom layer.
Alternatively you could just leave out the second Bror shelf, but no idea how that impacts the stability of the trolley. I chose to add new holes below the lowest holes to move the second Bror shelf there.
It stores 11-12 1kg spools per layer and side, so 44-48 spools in total.
The spool shelf could also work for the Work Bench and other Bror furniture, but I didn't test it.
The author marked this model as their own original creation.