Adjustable and comfortable. Great to wear while dancing or working out. Reduces injury and muscle strain during workouts. Also helps improve posture and release back pain. Ideal for diastasis recti (abdominal muscle separation after pregnancy)Materials: Breathable fabric neoprene, high elastic with double compression and acrylic bones enclosed in heavy canvas for extra support! Also helps prevent core and back strain while working out.  Suggested to wear during workouts for extra sweat! It has a comfortable fit unlike other waist trainers, so you can also wear throughout the day too. EASY WAY TO PICK YOUR BELT SIZE: Choose a size up from your normal shirt size for good fit. Belt is also adjustable.