1,gas spring for all kinds of office chairs 2,chrome or powder coating are available 3,with high quality and best price Gas springItem: HY ... is 845±2mm.(when it's Extended)1,Material: Steel2,Quality: Airproof and durable3,Chrome or Powder coating are all available4 ... ,Function: It would be adjustable and extendable by force7,Our gas spring get the certificate of TUV, SGS, LGA, CATAS. office chair ...