JL Audio M3 Series 7.7" Marine Coaxial Speakers w/Gloss White Sport Grilles - M3-770X-S-Gw [010-03068-00] Brand_Rule If you have multiple compatible

If you have multiple compatible Garmin devices on your boat

For polishing use dual action buffer

Bronze Thru-hull Wide Beam Transducer w/Depth & Temp - 12° Tilt

Non-Isolated Series

JL Audio M3 Series 7.7" Marine Coaxial Speakers w/Gloss White Sport Grilles - M3-770X-S-Gw [010-03068-00] Brand_Rule If you have multiple compatibleM3 Series 7. 7" Marine Coaxial Speakers with Gloss White Sport Grilles M3 770X S Gw PLAY BETTER Optimized for moderate power systems, M3 marine speakers are designed to produce powerful, smooth sound that is several steps beyond common marine speakers. Features: Amazing fidelity and affordability in marine settings Exceeds international standards for salt fog and UV exposure 3 Year Warranty DMA Optimized Woofers Proprietary motor, suspension and cone