Stability balls promote better balance, improved posture and increased flexibility. They are great for performing a variety of upper-body, lower-body, core, balance and rehabilitation exercises. Challenging for both the de-conditioned and the high-level athlete. Available in 55cm, 65cm, 75cm and 85cm. These Exercise balls have a foam texture (not a slippery surface).
Blue - 55cm - Recommended for 4'11" to 5'5 "
Silver - 65cm - Recommended for 5'5" to 5'11"
Green - 75cm - Recommended for 5'11" to 6'4 "
Blue - 85cm - Recommended for 6'4"and over
When you sit on it, knees should be @ 90 degrees