【Anti-Bursting】 - Our exercise ball is made of anti-bursting honeycomb structure, thicker and heavier than others. The anti-burst means that PROIRON exercise ball will slowly deflate when pierced, rather than bursting. 【Non-Slip Surface】 - The fitness ball has a non-slip surface, which is essential for a safe workout. The fitness ball is made of eco-friendly material, won't irritate your skin. 【Extra Thick】 - Our exercise ball have 2mm wall, thicker than normal yoga ball, load capacity is up to 300kg 【A Chair Or Birthing Ball】 - If you sit at a desk all day, you can use a gym ball as a chair to improve your core strength and balance while sitting. Plus, you can use a gym ball as a birthing ball for prenatal exercises, and to reduce discomfort during pregnancy and labour. 【Pick The Right Ball】 - This is black yoga ball, the ball size is 55-65cm (for Height 162cm-178cm) approximately.