Butterfly - SJA108(4D) 1. Adjustable headrest + 4D armrest 2. PP+GF Backframe + Adjustable lumbar support 3. High density molded foam with Seatcover 4. Functional mechanism 5. Class 3 black gaslift 6. Aluminum base can be passed 1136KG static pressure test 7. PU castors BIFMA test passed