The height of the wobble board can be adjusted to 3 different levels with the included adaptor. Large 15.75 inch / 40 cm surface makes it ideal for a variety of uses. Balance board has a textured non-slip surface for increased safety. Recommended by physical therapists, and other health, and fitness professionals, for exercise, therapy, and rehabilitation. Balanace board is packaged in an attractive box, and includes a detailed user's guide. Ages 4 and up.