24-Hour Task Chair with arms features a molded back with pronounced lumbar support. Adjust back height control easily when seated. Deep contours provide for "built-in" comfort, and foam padding in seat is extra durable for years of use. Arms adjust in height and width. Functions include pneumatic seat-height adjustment from 17-1/2" to 22-3/4", back-height adjustment, 360-degree swivel, tilt, tilt tension and tilt lock. Seat size is 21" wide x 19-3/4" deep. Back measures 18" x 18". Weight capacity is 300 lb. Task chair is certified by SCS to be in compliance with specific indoor air quality emission requirements. Meets or exceeds applicable ANSI/BIFMA standards.