describe Set of 5 silicone casters for office chair, stem diameter 11 mm, black Old plastic wheels can cause many problems. A few days are enough to tarnish a new floor To avoid this, most of the time we decide to buy carpet or plastic mats. This purchase protects our floors from scratches, preserves the design of the room and reduces damage to the comfort of working at the computer. Rubber wheels with a bearing system eliminate all problems. They are silent, move without resistance, do not interfere with the interior design and, most importantly, do not leave scratches on the floors. Thanks to their universal design, they emphasize both the elegance of an office chair and the aggressiveness of a gaming chair.