By deman, but I'm not sure if it fits the most popular chuckers & balls. The balls I use are 60mm Sportspet High Bounce ones and my dog absolutely loves them.
I've included the Fusion3D model if people need to modify it, but it's not the best of designs as I eyeballed a lot of it.
Should be printed with very low ( 4% ) infill.
The author marked this model as their own original creation.