RELIABLE HEAVY DUTY CONSTRUCTION – ATOMDOC 6 Maximum weight rating: 130 lbs EACH wheel! The heavy duty design supports up to 650 lbs as a set of 5. Compared to the traditional bearingless bracket, the new casters use a new bracket with a double bearing design, which is more stable and durable, the STRONGEST chair wheels on Amazon. UNIVERSAL STANDARD STEM SIZE(NOT FOR IKEA) – Orders come with a set of five ATOMDOC 6 that can easily be installed without tools or hardware. Just take your old casters out and push your new ones in, and you are done! Please Check that your chair is compatible. The stem size is 7/16"(11mm) diameter by 7/8"(22mm) length. IMPORTANT: Not for IKEA!! Suitable for 98% office chairs brands of Miller Steelcase, Aeron, Herman, Dxracer, Humanscale Freedom, Lazyboy Serta, Hon, Boss, etc. INCREDIBLY SMOOTH & QUIET –ATOMDOC’s chair wheels can keep your chairs moving smoothly and quietly. No more squeaking and rattling. Each wheel can steer 360° quietly and flexibly on any surface. Replace your standard plastic castors set and stop worrying about disturbing anyone. 100% SAFE FOR ALL FLOORS – Stop damaging your expensive hard wood floors and carpets with the poor quality wheels. ATOMDOC 6 rubber casters do not require chair mats at all. Enjoy carefree and safe glide on wood, hardwood, laminate, vinyl, tile and carpet floors throughout the day. ATOMDOC Fashionable Elemen – ATOMDOC’s chair wheels make your chairs look more fashion and more comfortable, which makes you feel satisfied with the fancy office chairs or the ordinary computer chairs. we have a no hassle 100% guarantee refund policy. ATOMDOC’s chair wheels will be the best choice to upgrade your chairs. ATOMDOC 6 Maximum weight rating: 130 lbs EACH wheel! The heavy duty design supports up to 650 lbs as a set of 5. Compared to the traditional bearingless bracket, the new casters use a new bracket with a double bearing design, which is more stable and durable, the STRONGEST chair wheels on Amazon.