The Balls are a modular wooden-volume system, each volume has been designed to be stacked on top of one another, allowing you to create a 180° volume, hence the name Balls. Moreover, all balls are made to fit onto a ball of a bigger size, you can for example fit a S1 onto a L1 and put both on top of an XL2.
This system allows you to perfectly regulate your boulders and routes, it also let you completly change the profil of a panel, pretty handy on a comp wall or for a gym.