Remixed from https://www.printables.com/model/3407 by @Sneaks and https://www.printables.com/model/622012 by @shailesh_1005383.

Slides over the right hand side of the x-axis on the Elegoo Neptune 4 Max, it might work with other Neptune 4 models but I have not tried it. Allows you to attach Sneaks compatible articulated arm parts. Note the mount is not directly attached to the z-axis but does move in the z-axis with the print head.