Carb rebuild kit, Keyster manufactured in Japan, complete rebuild kit for your Z50 K3 and K4 carb. Kit contains: Chamber Gasket, Needle Valve, Needle jet, “E” Clip, Spring seat, Air screw, Air screw spring, Main jet #55, O-Ring (2), Throttle screw (2), Spring for throttle screw, Needle jet, Top cover gasket.