The Coregeous ball allows you to take your training to the next level, working the deepest abdominal muscles. It appears in Jill Miller's Yoga Tune Up DVD, which guides you through exercises to strengthen your core, improve posture, and tone your entire torso. - Allows access to deep abdominal muscles - Soft and elastic exterior comfortable on the skin - Strengthens the entire torso and improves posture - Helps tone all muscles in the torso Product dimensions: 22.86 cm wide x 22.86 cm high x 22.86 cm long Product weight: 0.0997903214 kg