A mold I made for making Destiny Ghost stress balls. This contains bands on the outside for rubber bands to hold the mold together.

– This never fully worked and the model will probably need to be adjusted. –

Printed at 15% inner fill with 4mm walls and supports.

I used this material for the stress balls:

https://www.amazon.com/gp/product/B00I6LYDE4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1