This is a Luer lock to R3/8" thread (BSPT) adapter that is suitable for printing with an resin printer. For example, it lets you connect syringes to pneumatic fittings, as seen in the picture.
Source code (.stp & .3dm) is also provided, should you want to modify the design for your own purpose. Please share your prints!
The author marked this model as their own original creation.