Mercury - Enertia ECO 3-Blade Stainless Steel Propeller 16" Diameter x 21" Pitch Left-Hand Rotation 3 Blades X7 Stainless Steel Polished Finish 8M0151258. Overview. Some props save fuel. Others deliver speed. The Mercury Enertia ECO 3-Blade Stainless Steel Propeller (Part Number 8M0151258) does both - and it does it beautifully. This prop has a way of making your boat feel balanced and responsive, as if it's anticipating every move you make. It is the kind of prop you trust on long runs when eff