Genuine Losi spare/option part.The piston is now delrin with a much tighter tolerance to the shock bodies. This creates a much better wearing part and allows the shock to work smoother. Kit includes a complete set of 24 pistons four each with 2.0 / 2.1 / 2.2 / 2.3 / 2.4 / 2.5 holes for a truly tunable shock.