Balt Circulation Stool for Sit Stand Desks, Black Seat Back, Five Star Base, Casters (34798) Black polypropylene seat and back, contoured for natural support and comfort. Seat features a 16 Degree slope for a natural seating position and is pneumatically adjustable from 20" to 29" high, making it ideal for todays modern sit to stand workstations. Independently adjustable foot rest adds comfort. Stool rolls easily on a 5-star base with 2" casters.