3397BV. Rated for 24/7 use, the back of this intensive-use chair has ample support and ergonomic shaping to provide comfort and may help reduce fatigue; breathable nylon mesh keeps users cool and comfortable throughout every workday. Solid construction supports up to 500 lbs. Back height adjustment that may help support correct posture and a reinforced mechanism with back tilt that may help support a reclined position to allow a beneficial rocking motion throughout the day. Optional Adjustable T-Pad Arms sold separately. Recommended Applications: General Office & Task; Specialty�Big & Tall, 24/7; Seat/Back Color: Black; Arms Included: No; Pneumatic Seat Height Adjustment: Yes.