Seat measures 16″ in diameter.
Physician Stool w/ Black Base, Knob Handle, Std.-High, Tan Adjusts in height with a single lever 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:Upholstered BackrestCrescent BackrestWeight capacity 300 lbs. This seating has three different 24″ diameter base styles and two different height adjustments.