You will find that the Formiden branding is not too flashy, which suits a neat setup well.
12V 40A Heavy Duty SPST 4-Pin Automotive Relay (Pack of 2) for Universal Use
This unit carries the Schneider Electric brand, and you will find that it lines up with familiar product families.
You can tell this heavy duty relay is made for tough spots, with thicker casing than many alternatives.