Mastery Mart Office Chair Gas Lift Cylinder Replacement, 7.6'', Matte Black Product Details ??Adjustable Height 7.6 inches?The minimum height of the fully chair piston is: 15.2 inches (38.5cm), the fully expanded height is: 22.4 inches (57cm) and it has an adjustable height of 7.6 inches, which allows you to rise higher. (Note: measured before purchase) ??Universal Fit Size for Most Chairs?The outer cylinder diameter connected to the base is 2 inches (5 cm), and the inner cylinder diameter of the gas lift connected to the chair is 1.1 inches (2.8 cm). This pneumatic piston cylinder will fit almost every office chair on the market including herman miller aeron. Please confirm these measurements before making a purchase. ??Upgraded Class 4 Gas Cylinder?Mastery Mart's office chair cylinder replacement is made of premium steel. This heavy-duty gas lift cylinder is manufactured to meet the highest industry standard (BIFMA/ANSI), the lift has a maximum capacity of up to 450 LBs/ 204KGs. ??Eliminate Sinking Concerns?Prevent sinking issues by removing the old cylinder using a hammer or wrench. Simply assemble our new cylinder into the base and attach the seat. Our office chair lift provides seamless 360-degree rotation. ??100% Satisfaction Guaranteed?For any issues with using our chair shock replacement, please don't hesitate to contact us. We are here to provide guidance, offer replacements, or process refunds, depending on your specific case. Your satisfaction is our priority. Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.