Diameter: 55 cm. Gymnic Ball: The Gymnic fitness ball with plug closure is used in pregnancy and therapeutic gymnastics. It is also a very popular training device in health and rehabilitation sports. Whether you sit on it, bounce, or roll over it, the Gymnic fitness balls offer a variety of exercises. A detailed exercise guide is included with your order. This gymnastic ball is also very popular for the trend sport Beach Jumping. The right Gymnic fitness ball based on body height: up to 152 cm: 45 cm, 152–169 cm: 55 cm, 164–181 cm: 65 cm, 182–192 cm: 75 cm. These ball sizes are used for different gymnastic exercises, so there are no specific body height requirements. Load capacity: up to 300 kg, up to 250 kg, up to 200 kg, up to 150 kg. Ball type: sitting ball, large gymnastic ball, fitness ball. Area of use: rehabilitation, therapy. Max load capacity: 300 kg. Material: plastic (latex-free).