The Topstar Sitness 20 in purple / violet is supposed to automatically straighten your pelvis and thus make it easier for you to work at your desk. And indeed: When you sit down on the Topstar Sitness 20, you are welcomed by a pleasant, working gas spring. The stool ensures that you automatically place your feet on the lower rubber foot ring, thereby straightening your pelvis or spine. The intervertebral discs are thus relieved and the spine is brought into its natural S-shape. The Sitness 20 from Topstar also has an infinitely variable seat height adjustment with Toplift and the seat itself is of course ergonomically shaped. The base is extremely stable and is mounted on a patented rubber tyre (original Swiss-Walser patent). The air pressure is adjustable to your needs. The metal foot plate is made of chrome.