Designed for easy installation, this mounting adapter plate enables you to seamlessly integrate a JL Audio MediaMaster MM50 or MMR-40 receiver into a marine radio opening that was previously larger. Crafted from a solid piece of marine-grade, machined aluminum, it features a durable black anodized finish that provides resistance against UV rays and corrosion. Included with the plate are stainless-steel hardware and a comprehensive full-surface gasket, guaranteeing a secure and watertight fit during installation. The countersunk mounting holes are cleverly concealed behind your MediaMaster's trim ring, resulting in a sleek and professional-looking setup.