The ErgoPro 321 is the classic version of Productive Practices' ergonomically designed operatory stools, which combines unparalleled support with an elegant design. Its mechanism is the core of the stool's ability to adjust to an individual's personal seating requirements. Spring seat tilt and back tilt allows total control and adjustment for the individual user who wants to sit and lock the stool in a stable position. The backrest and entire stool can be individually adjusted for height.