This is a Orange Pi Zero 3 rack mount. Designed to fit with:

• https://www.thingiverse.com/thing:3167883 - used as a reference
• https://www.thingiverse.com/thing:1936196

This thing is also compatible with this USB extension board

• https://www.exegate.com/catalogue/case/caseacc/port/ex298293.html

Printed as one piece, no supports