2" Replacement Office Chair or Stool Caster Wheels - with Brake (Set of 5) - S2421-5 2" (50mm) wheel size with manual locking brake holds wheels from rolling Standard 7/16"x7/8" (11mm x 22mm) wire grip ring mounting stem (universal) Standard hard nylon plastic wheels - Ideal for use on carpeted surfaces and plastic chair mats Set of 5 Casters Black