The 55 cm large, two-colored Reebok exercise ball is one of the most versatile devices for general fitness. It offers a variety of exercises to strengthen the upper body, improve posture, and enhance flexibility. The reinforced bottom provides additional stability and prevents the ball from rolling away. Although they often look similar, exercise balls come in different sizes and materials. The 55 cm ball is made from extra-dense rubber and is suitable for users between 155 cm and 167 cm tall. Choosing the right size of the ball is very important to achieve maximum efficiency for your workout. You can find the correct diameter by sitting upright on the ball and ensuring your knees form a 90-degree angle. Your height is not the only factor in selecting the correct ball. The Reebok exercise balls are flexible and provide resistance, so your weight is also an important consideration. To enhance your sit-ups, tricep dips, forearm planks, and other stability exercises, the ball features technology that prevents bursting under point loads. The high-quality gray-black exercise ball is available in three sizes (55 / 65 / 75 cm).