OpenSCAD (https://www.openscad.org) file to generate a circular platform of defined diameter. If printed in PLA (https://en.wikipedia.org/wiki/Polylactic_acid), it will be an ecological and biodegradable tool to optimize your bonsai root development. It has been designed with the aim of educating the radial growth of the roots avoiding entanglements between them and a balanced distribution to obtain the best nebari of your future bonsai. The spaced and concentric divisions provide a correct channeling of root growth. It should be used buried a few centimeters from the surface with the future bonsai fixed in its center, leaving a couple of centimeters at least from the edge of the platform to the wall of the pot to facilitate the descent of the roots in search of nutrients. In this way you will obtain a perfect nebari and a balanced radial distribution of the roots when growing on the platform in search of the edge and the lower substrate.