2x2 Gridfinity guitar pedal holder.
Has a trough in the middle for the little nub on Boss pedals. Currently using it to hold a DS-1, TU-2, and DD-3. There's wiggle room inside so it should hold some larger pedals as well.
It fits (barely) into an Ikea Alex drawer if placed in the middle of one of the larger drawers (not enough clearance if placed near sides of the drawer).
The author marked this model as their own original creation.