You are buying one new GREEN Timing / Cam Chain Tensioner Adjuster. IF YOU NEED 2 BUY 2. NEW READY TO INSTALL. VERY SIMPLE DESIGN. EASY TO USE. COMES WITH GASKET MOUNTING INSTRUCTIONS. - THIS IS ON HAND, IN STOCK. WE CAN SHIP NOW!! WE SHIP VERY FAST! THIS FITS KAWASAKI: - 1985 to 1987 NINJA 600 / ZX600 - A1,A2,A3 - 1987 NINJA 600RX / ZX600 - B1 - 1988 to 1997 NINJA 600R / ZX600 - C1,C2,C3,C4,C5,C6,C7,C8,C8,C10 - 1990 to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