LIGHTWEIGHT ✔ The high-quality and sturdy plastic surface of the wheels makes them extremely smooth on the demanding fabric surface. Thus, you can move your office chair easily. | BRAKES ✔ The 50 mm carpet rolls have load-dependent brakes – they only grip when not under load and prevent unintentional rolling away // When loaded, the wheels are pleasantly smooth – no annoying braking resistance. | EASY MOUNTING ✔ The tools are easy to change without tools: pull out the old rollers from the base and simply insert the new AMSTYLE rollers – super comfortable & easy! | SUITABLE ✔ Due to the standard size of 11 mm, the silver metal pins fit into almost any office chair – exceptions are Ikea & Topstar chairs, because the base of these chairs has a 10 mm hole. | SAFETY ✔ The office chair castors constructed according to DIN EN 12529 are a reliable everyday helper. If you do not like the swivel chairs, you will get your money back.