Scope I made for my kids a while back that slides on their Nerf Guns rail system.
Prints in place, no support. Cut off the four (4) lilypad hold down...s after printing (they were added to give additional contact area on the bed for additional adhesion).
As usual I have included the design in multiple formats so you can modify it. I have the original Solidworks file, and exports into STEP and X_T. Modify to your hearts content.
3d model print parameters
I have printed them in PETG and PLA. Both seem to function and print equally well on this design....