chairpartsonline 2" Replacement Office Chair or Table Caster Wheels - with Brake (Set of 4) - S2421-4/Bag 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 Standard hard nylon plastic wheels - Ideal for use on carpeted surfaces and plastic chair mats Set of 4 Casters Black