Made from the proven material of Blackroll. A combination of two Blackroll balls with a diameter of 8 cm. Usable like the Blackroll ball and ideal for rolling out the back (with a recess for the spine). Designed for targeted application, small, lightweight, and perfect for on-the-go use. Suitable for use on the floor and against the wall. Particularly effective for intensely massaging the muscles in the back, glutes, thighs, and feet. Ultra-lightweight, free from propellants and other chemical agents, odorless, durable, abrasion-resistant, and water-insoluble. Good resistance to chemicals and oils, physiologically safe, and thermally stable.