Deluxe Futura Style casters are designed exclusively for “euro-style” chairs. Specially designed 1-1/2″ diameter neck fits 1-1/2″ diameter chair bases (sold separately), creating the illusion of chair leg and caster being one unit. Use these 2-3/16″ diameter casters with hard wheels on carpeting. Weight rating is 100 lb. per caster. Casters include 7/16″ x 7/8″ B stems and 3/8″ x 1″ K stems.