Task Chair- Height Adjustment- 19-.25in.x25-.75in.x40in.- Blue Task chair features pneumatic seat-height adjustment, 360-degree swivel, tilt, tilt tension and tilt lock. Design includes a fully padded 17-1/4 wide back and seat, and 2-1/2 hooded dual-wheel casters. Seat size is 18-1/2 wide x 18-3/4 deep. Seat-to-floor height ranges from 18 to 22-1/4 . Back size is 17-1/4 wide x 18-3/4 high from the seat. Height-adjustable arms are sold separately. Chair meets or exceeds applicable ANSI/BIFMA and ISTA performance standards.