Gas spring adjusts ShopMaster Model 101's seat height from 16-21 in. Molded PUR seat, steel powder-coated tool tray, five 3 in. casters, and gas spring dust shield provide ergonomic support. Benchmaster Model 102 also has molded PUR seat that adjusts from 21-31 in. Adjustable-height back support tilts 30 deg, free float or locked. Five gliders ease movement.