This paper covers the modeling and nonlinear attitude control of the Cubli. a cube with three reaction wheels mounted on orthogonal faces that becomes a reaction wheel based 3D inverted pendulum when positioned in one of its vertices. The proposed approach utilizes quaternions instead of Euler angles as feedback control states. A nice advantage of quaternions. https://parisnaturalfoodes.shop/product-category/thinning-hair-shampoo/