The massage ball massages and relaxes tense muscle groups optimally through vibrations and its ergonomic shape The size allows it to perfectly reach trigger points. Small and practical - perfect for on the go. 2 intensity levels. Easy to clean, soft touch surface, 7.5 cm diameter. Versatile use - at home and on the go. Can be used while standing, lying and sitting. 3 x 1.5V AAA batteries included.