Hey! Replace the original hard plastic wheels, do not make noise to affect your colleagues or family. Quickly replace the ATOMDOC newly revolutionary casters, quadruple quiet, quadruple stable. No longer bothering other people! Why not experience such a good wheel? Just pull out the old casters and insert the new, pushing them in until they lock firmly into place, no tools needed. The stem size is 7/16" diameter by 7/8" length. This is the standard size of almost all office chair models and brands. To check compatibility, pull out your current chair wheels and measure the stem. The ATOMDOC protector castor replacement wheels are made from protective nylon rubber and encased in soft polyurethane material, so they will not leave any marks or scratches, including hardwood, laminate, vinyl, tile, carpet.