These are construction links. I made these Links to help me build costumes.
These links are still being worked on so design be aware that these change over time.
Some design specifications:
The links are 30mm by 15mm by 5mm
The holes are spaced 15mm. Diameter of the holes are 10mm.
The pins are 9.6mm big so they have a tight fit.
Both holes and pins (big and small) have 16 teeth.
The smaller holes inside the pins have a diameter of 8.6.
The smaller pins/plugs have a diameter of 8.3mm.