For teachers or students in high-traffic technology labs or classrooms with intensive keyboard use. Pneumatic seat height adjustment from 16" to 20-1/2". Plastic seat and back. Black, five-point plastic base. Dual-wheel casters. Manufacturer's ten-year warranty. 24-1/8w x 24-1/8d x 30 to 34-1/2h. Shpg. wt. 23 lbs.