▻ANSI BIFMA Quality verification standard ▻nylon+fiber plastic back frame in black color, with adjustable lumbar, swing back function ▻Adjustable headrest ▻Mesh back ,fabric seat ▻2D adjustable arm，grade 6，PU soft armrest top ▻high density molded foam ▻Multi-lock mechanism,3 locking positions ▻holder between back and mechanism：chrome ▻Back angle :100°~140° ▻Class 3 SGS certified gas lift 80MM ▻¢700MM 5 star aluminium base SGS certified ，at least 98,000 times friction