All eight convertible top hydraulic cylinders, hydraulic hoses, and the hydraulic pump for your 370Z are sold by Nissan only as a complete set, part number 97093K or 970931-ET0A. No need to buy a complete hydraulic system, when you can have your components upgraded by Top Hydraulics for far less money! All components within the convertible top hydraulic system are rebuildable and replaceable. Nissan Dealers do not generally know this, because Nissan does not get the components supplied separately, and thus the dealers are only trained to replace complete hydraulic systems. Top Hydraulics manufactures superior replacement hydraulic lines, supplied with o-rings for both ends and an installation tool. The pump rebuild makes the pumps better than brand new ones. We upgrade your cylinder(s) by replacing the tiny OEM rod seal with a much larger one made of superior materials, and adding custom caps made of CNC machined stainless steel to accommodate these superior seals. Our seals are not sensitive to water and are resistant to most additives in hydraulic fluid. This results in a much longer service life than the standard OEM cylinders for a fraction of the price. Top Hydraulics' standard warranty is 3 years on rebuilds/upgrades of convertible top cylinders and hydraulic pumps, and on new hydraulic hoses.