Review on High-Performance 1 Pack 40/30 AMP 12 V DC Waterproof Relay and Harness - Heavy Duty 12 AWG Tinned Copper Wires, 5-PIN SPDT Bosch Style Automotive Relay by Todd Phillips

Time will tell if they are reliable and internals are to specification but my overall impression of this relay is overwhelmingly positive. First, it doesn't seem cheap. It's a good weight and feels extremely heavy, with very thick plastic and a shell so tight that I struggled to fit the two halves together (do this before connecting and/or installing or you'll have to almost certainly take it out again ). I very much doubt that I can separate them. In addition, I was surprised to see that all of the wire was solid stranded copper and was 12 gauge. I know it says it in the title/description, but to be honest I wasn't expecting it. When corners are cut, cheap wiring is usually a very common place to do it. Given the HD feel, solid copper wires, and apparently solid waterproofing, I have no reason to think they skimped on the interior. Also as a side note I appreciate the schematics in the product description. I have no knowledge of automotive electrics but I wanted to wire the fog lights in parallel with my headlights but didn't want the lights to be powered from the headlight switch so I disconnected that relay from the headlight wire and now only the relay is powered by powered it, unlike both fog lights. This is much safer and should extend the life of an expensive 45 year old light switch. I'll almost certainly buy another one when I add another external accessory.