Monroe Magnum Axle Shaft Dampers are designed to replace many late model original equipment dampers. Product Features:1/2 inch Piston Rod: Heavy-duty nitrocarburized rod for long service lifeAll Weather Fluid: Contains special modifiers to reduce friction and ensure smooth rod reaction.Full Displaced Valving: Better valving range on both the compression and extension cycles of the unit for a smooth comfortable ride.Micro-Cellular Gas Design: Allows unit to be mounted horizontally.Sintered Iron Piston: Stronger than traditional metals, enhances durability for longer service life.Special Seal: 'Self-lubricating' fluid seal designed to retain gas without excessive wear or friction.