... Strut for Office Chair / Bar Stool / Table2. Stroke(mm): 80 / 100 / 120 / 140 / 160 / 230 / 260 / 330,Etc.3. Surface: Black ... 3 / Class 4 5. SGS BIFMA X5.1(100,000 Times Testing)6, Pressure(N): 300--4507, Bottom Color: White / Black / Orange ...