Power Tray Bluesea 12 circuit

I have Blue Sea 12 circuit by Power Tray brand new never minstalled. I originally bought this to do lights and other electrical needs but never got a round to it. Ended up saving up for a house and picked up a new boat so the mods stopped. Since I'm getting back into modding the rig I've decided to go with a different route and grab the switch pro one. Looking to get what I got it for. Power Tray website says back ordered I believe, either way looking to let this one go so I can grab the other one. Located in the Bay Area CA

$250

 

Sunday bump.

 

So ive yet to start my electrical and im pretty clueless...

the only reason i didnt jump on this the other day is im not sure how many relays i need, where i need them, how to install them, etc lol

So this tray doesnt have room for relays, so im a little hesitant... but im not even sure i need that lol

 

So im not 100 percent sure about the relays. From my readings it depends on the amps drawn. As far as for relays I see a bunch of ppl mount them on the side in between fuse box and fender.