<b> NOT FIT 40mm Diameter Base Hole.<br> NOT FIT 40mm Diameter Base Hole.<br> <br>Gas cylinder may possible break the package when the button is pressed and triggered during the shippment.<br> <br>If received Empty Package or not perfect gas cylinder, please contact seller for free replacement, instead of leave negative review directly. <br> <br><br></b> <b>Product Description<br></b> Size: 6" (150mm) marked as 6.3" (160mm) <br> Adjustment Height (Piston Travel): 6" (150mm)<br> <br> Cylinder Overall Length: 12.4"-18.3" (315-465mm), <br> Smaller tube Length: 2.8" (70mm), <br> Bigger tube Length: 9.6" (245mm)<br> <br> Diameter of the outside metal tube is 1.57" / 40mm for bottom, 2" /50mm for above body.<br> Diameter of the smaller metal tube is 1.1" / 28mm.<br> Diameter of the plastic button is around 10mm.<br> <br> <b>Features:<br></b> - Adjust height of office chairs<br> - Class 4 level, Top Quality Level, Heavy Duty Construction, Specialized for Heavy Person,BIFMA Plus Quality<br> - Allows full 360 degree rotation<br> <br> If your gas cylinder has worn out on your chair or stool, you may want to consider this Heavy Duty option. This replacement office chair gas lift cylinder is more heavy duty than standard chair gas lift cylinders. It's a great replacement option for damaged or worn out gas lifts on office chairs, task chairs, executive chairs, & more! While this gas cylinder will fit the majority of chairs and stools, it will not fit all. Please measure your original cylinder to be sure. Minimal dimensional differences shouldn't alter performance of lift when installed. Always remove gas cylinder with care and never heat or puncture. <br><br> <b>if product missing, what shall I do ?</b><br> If happens to receive nothing but an empty package, No worry, just contact MySit by message/email to offer free warranty gas lift.<br> <b>if product not fit or not work, what shall I do ?</b><br> Please contact seller to offer good solution.