The Blackroll Booster Set Slim is a combination of the Blackroll Slim foam roller and the Blackroll Booster. This set combines vibrations with classic fascia training for a more intense massage. The travel-friendly Blackroll Slim can be used anywhere and is extremely effective. The Booster?s continuously adjustable vibrations from 12-56 Hz intensify the effects of the massage, loosening tight muscles and reducing pain. Users can exercise with the roll and enjoy the added advantages of deep reaching vibrations.