This is a printable set of connectors that you can combinate as you can and create your original shelf, rack or others. Inner diameter of connectors is 28 milimeters. I designed mine own PC table. I used wooden rods and theese printed connectors to create this PC table. Every connector has a gap for a screw to fix rods inside of connector. There is also the main file to modify the connectors you need. Stl files are prepared for every connector separately. You can use corner connectors, several variations of angle connectors, T profiles and combinate them together.