Now improved with metal ball bearings for a smoother, easier spin. Provides lots of vestibular/movement input in a small space. Large 16" textured top surface can easily be adjusted to change angle of slope to match level of skill. The wide 18" base provides maximum stability and a built in carry handle. Try sitting, kneeling, lying down. Maximum weight is NOW 200 pounds. No assembly is required. (Adult supervision, caution and common sense is recommended when using this and any moving.) Colors may vary. *Sorry - this item DOES NOT qualify for discounted or free shipping.