OPTP offers three ball sizes to accomodate various body areas. Inflate or deflate balls as needed to adjust size or firmness. Needle inflating pump required for inflation (sold separately). Supports up to 660 pounds. Balls are shipped partially deflated.
The Beginner Ball is soft and used for beginners, those with osteoporosis, arthritis or limited flexibility. 21cm (8¼") in diameter.
The Intermediate Ball is firm and smaller for detail work; especially the shoulder, neck, abdomen, pelvis and arm. 17cm (6½") in diameter. Assorted colors.
The Advanced Ball is the firmest and is used for spinal work or specific muscle release. 18cm (7¼") in diameter.