A nice touch is the bright ring around the Emergency Stop Module, helping you locate it fast.
4-pin 40/30Amp 12V DC Waterproof Automotive Relay with Heavy-Duty Wire
what stands out about this relay is that the label shows the brand NOVITA, which some folks will recognize.
You will find that one box includes the relay base w/ relay, making setup feel straightforward and tidy.
You will find that the 70*20*18mm / 2.75*0.78*0.7" size works well in modular builds.