Its a 29 gal Ocianic nano cube. It comes with 40# of live sand, 20# of live rock, clown fish, diamond jaw fish, valentine puffer, emerald crab, some blue leg and red leg crabs. Also includes a protein skimmer, extra salt, and a heater plus extras. Its all for $175. I would add another 10 lbs of live rock or base rock to it if I buy it. This would be my first salt tank. I was actually going to set up a 20 gal salt tank on Monday with the help of a friend that has lots of salt experience, until I came across this deal. Given I don't know a whole lot on salt water tank mates is this an ok selection of specimens to live together.