Size SelectionPlease measure and confirm what size chair wheels is suitable for your chair before purchasing. This saves a lot of time. These hard floor castors have a 11 mm x 22 mm pin. They do not fit NitroConcepts chairs. Silent + Smooth + DurableGlide completely without noise on your office chair. Even in the evening in the home office, no one will be disturbed by your work. Perfect for gamers who like to play at night. No ScratchesOur castor wheels will NEVER scratch, smudge or damage your floors. Enjoy a carefree, safe glide across wood, hardwood, laminate, vinyl, tile and carpet floors all day long. Good Load BearingNot all office chair castors are created equal. Our office chair wheels replacement are made from industrial-grade steel, precision ball bearings, and durable polyurethane. Chair castors can support loads up 397 pounds (180kg)! Compatible with Most 11mm Office ChairsFor wheelchairs with 11 mm x 22 mm pins: suitable for any desk chair when this supports 11 mm wheels. (NOTE: IKEA uses 10 mm wheels and many Topstar office chairs have 10 mm bore.)