Nitro Stainless Steel Shocks. Stainless steel 38mm damper unit fully re-buildable, 18mm piston rod, 10 position damping adjustment with automatic compression / rebound balance. 73mm outside diameter stainless steel spring, silver anodised aluminium fittings. Fully progressive spring pre-load adjustment. Supplied as complete pair with end mounting bushes, spring adjusting C spanner and 2.5mm hexagon key. These units are designed to be fitted with the damping adjuster at the bottom. 2-year guarantee.