This is designed for the Kong X-Small balls (4.4 cm) but I think it will work with any ball from 4 to 5 cm. It was designed for my wife as her back was hurting from throwing the ball so often. This has helped massively and allows her to throw it further too.

If printed in ABS, it is very strudy and will last. It can also be printed in PLA or PETG but the claw arms will snap after a lot of use