2" Replacement office task chair caster wheels w/ 7/16" x 7/8" grip ring mounting stem- Set of 5 - S2227-5 2" (50mm) hooded wheels Standard 7/16"x7/8" (11mm x 22mm) wire grip ring stem (universal) fits most standard chair bases Hard nylon plastic wheels - Ideal for use on carpet and plastic chair mats Black Set of 5 Casters