5-legged base with 2” casters allow for easy mobility. The LARGE 16” diameter round seat can be adjusted from 22” to 28” tall. The 18" Stainless Steel foot ring is strong enough to stand on. With a weight capacity of 400 lbs it is the largest capacity on hte market. It has comes standard with "Sit-down" locking casters that only lock when seated (traditional locking casters also available).