Office-Chair Caster Rubber Wheels for Hardwood - KATU BG506-38 - 2 Inch Diameter with Standard Stem. Safe for Hardwood Floors, Smoothness and Quietness - (Set of 5) Color Black & Gray &gt; KEEP YOUR FLOOR SAFE &gt; Resistant swivel office chair casters rubber wheels with a layer of Polyurethane (PU) material - No more scratches on hardwood, woodfloors, laminate, tiles, slate, marble, and all other hard floor surfaces. With this casters you can forget the use of cheap desk or chair mats, without the chair mat your furniture, workspace, gaming space, will have a modern and unique looking. &gt; STANDARD SIZE &gt; This office chair caster wheels comes with the standard stem size: 11mm (7/16") diameter, 22mm (7/8") length. this stem size is the regular used in most office chairs, desk chairs, task chairs, racing chair and is compatible with most brands such as Herman Miller, Humanscale, Steelcase, Erg, Alera, Homall, Amazon Basics & more, Please before ordering make sure that the stem size match with you chair base. Check last image for more sizes. &gt; HEAVY DUTY &gt; Maximum Weight Rating: 110 lbs. per wheel (Set of 5 supports 550 lbs.) when we said that this set will support 550 lbs. it will, we sold already thousands of units with excellent results and no complains about the casters broke, this office chair rubber casters are the perfect replacement for you desk chair or office chair. &gt; 5 YEARS WARRANTY &gt; Because we know our products we are totally confidence to provide a 5 years warranty, you can rest assure that this set of 5 casters will give you the security you need. &gt; SMOOTH MOVEMENTS &gt; This wheels for office chairs are lubricated with Lithium based grease for smooth movement and because they are also made with a layer of rubber they are going to provide you the best ride ever. You are not going to regret that you choose the Katu Casters set for your chair.