This is a parameterized boomerang model made in Onshape.
"Parameterized" means that in the model, there are variables for the elbow angle, the arm lengths, thickness, etc., which can be manipulated and the model updates accordingly. This allows you to generate an infinite number of different boomerang shapes.
A 3d print of this model should actually fly and return when thrown properly. I haven't made one yet, though.
The Onshape model can be found here: