I designed this 3/8 metric socket holder for my Kobalt socket set. The holes are made to fit with about 1mm extra space. Note: the Kobalt 3/8 deep sockets are not the same external dimension as the shallow sockets. This model is for the deep sockets. I wanted to build this on a 4x2 so I had more options in my tool drawer. I used the gridfinity box template that has improved magnet holes and I didn't need to use supports, YMMV.
The author marked this model as their own original creation.