I just bought the same thing from another vendor on Amazon (I think that there is somewhere a full bunch of chinese parts manufacturers that build the same parts on Amazon...). This is the link :
relay box
I had a close look to the thing when it came home: looks not so bad. Relays are standard 40A NO/NC, cable size looks OK as long as you don't have more than 30Amps of current.
My project is to work on the lights of my 70 duster, and I am planning to have at least 3 relays wired:
one for low beam headlamps (2 x 55w=110w, so approx 9.1 Amps) fuse will be 16A, cables will be 2.5 mm²
one for hi beam headlamps (2 x 60w=120w, so 10 Amps) fuse will be 16A, cables will be 2.5 mm²
one for horn (might go as well to a air horn?), tbd.
The three remaining relays will be spare ones, maybe some day I will be adding extra headlamps/fog lamps?
Using a relay will ensure that the requested amount of current will feed the lamps with no restriction due to old headlamp switch/poor connections.
The same with the horn (if I use an air compressor): I don't like the idea of having high current inside the dashboard...
