The product is a Martyr 280 Volvo dual prop aluminum anode for boats. It is a replacement part for Volvo outboard engines and is designed to protect the engine from corrosion. The anode is made of aluminum and is compatible with dual propeller systems. The product is being sold on eBay Motors and the seller has provided a description that should be read before purchasing. FINAL SALE, NO RETURNS, CLOSEOUT SALE