I needed a holder for a cicular PCB with 3 holes to hold it.
This is it, fully customizable.

Self explanatory.

1/the pins have a flat structure to allow printing. This flat structure must be carefully removed after printing to reveal the pins

2/even with the flat piece, printing the pins can be problematic if it sticks bad to the platform. Print with a raft to avoid this.

3/there is a base and a top. The top clicks on the base to close it.