Ritter 276 Air Lift Stool Hand Release with Locking CastersRitter stools by Midmark provide optimal comfort, support and stability. The star shaped base design allows for closer access to the patient and stable, easy maneuverability. Stability Chrome five leg caster base and hoodoptional glides make it stationary if you choose Comfort Wide, amply padded seat is constructed of dense foam while a bead less upholstery seam eliminates edges from pressing into your legs Simplicity Pneumatic seat height adjustment