Pneumatic Lab Stool, Backless, Supports Up to 250 lb, 17" to 22" Seat Height, Black Seat, Chrome BaseSafco Lab Stool features an easy to clean generously padded vinyl seat on a 5 star chrome base. Height adjusts to meet workplace requirements in hospitals, schools, warehouses, research facilities and other lab environments. Pneumatic lever provides easy height adjustment from 17" to 22" for a comfortable, personalized fit. Heavy duty 5 star polihsed aluminum base with swivel wheels allows 360 degree motion on both carpet and hard floors for optimal