This drafting stool features contoured back and seat to help to relieve back-strain. It has the Pneumatic gas lift seat height adjustment to raise the seat from 28 inch to 33 inch. The large 27-Inch nylon base will provide greater stability. It is equipted with hoode double wheel casters, and optional glides can be used in place of casters to stop this chair from rooling. With option of no arms, adjustable arms or loop arms. Item includes office chair with additional strong 2-Inch diameter chrome foot ring to convert chair into drafting stool. Overall size of the chair is 44.5-Inch - 49.5-InchH and the seat height is 26.5-Inch - 31.5-Inch.