You can tell this heavy duty relay is made for tough spots, with thicker casing than many alternatives.
2 Pack 12V 200A Heavy Duty SPST Relays for Automotive Marine Truck Split Charge
You will find that these relays come in a sleek black color, blending discreetly into most panels without drawing attention.
A nice touch is how this heavy duty switch relay snaps cleanly and stays put when mounted.
The relay runs on DC 12V, so it's a good match for battery-backed systems you already have.