This paint shaker attachment fits into massage guns with an approx. 19.5mm “hole”. This model was specifically designed for a an Aeros Recovery massage gun.
Two grommets of appropriate size are needed to help secure the attachment in the gun. Rubber band slots allow you to secure paints of all sizes. I have found this very useful for shaking all paints, particularly contrast paints.
The author marked this model as their own original creation.