This mod is to attach two wooden grid side tables together. I used this to create a litterbox for my rabbit. You will need screws to attach the side tables together, the holes are 5mm, and they're 6mm wide.

Product on Amazon: IZLHOME Wooden Grid Side Table for Indoor/Outdoor,Small Coffee Table for Boho Corner/Patio/Living Room,Storage Bin Deck Box for Cushions,Toys,Furniture Covers,Etc.Original Wood Color