a height adjustable work seat is disclosed . the work seat is collapsible and extendable , and has a base , a seat pan and four folding and lockable legs . four wheels are mounted to the bottom of the base . the folding legs connect the seat pan to the base . each folding leg pivots at the base , the seat pan and a center pivot . the seat pan is at a maximum height relative to the base with the four folding legs fully extended . the seat pan is at a minimum height relative to the base with the four folding legs fully folded . a releasable locking mechanism secures each of the folding legs in a fully extended condition . one or more crossbars may connect opposing sleeve locks , aiding in locking , unlocking , folding or extending the pair of legs between which each crossbar extends . the seat pan may have a seatback .