Seat measures 16″ in diameter.
Green Adjusts in height with a 180 degree D-shaped handle under the seat.3 different base configurations:Black CompositeBright ChromeAluminum Base with Toe Caps2 different pneumatic height adjustmentsStandard: 17″-22″Medium: 19″-26″High: 23″-32″2 Backrest options:B-Upholstered BackrestCB-Crescent BackrestWeight capacity 300 lbs. Physician Stool w/ Chrome Base, D handle, Std.Available with two backrest options.