Nothing, and I mean nothing is assembled upon arrival. This is for my 15 year old son. It looks cool but make sure you have about 2.5 hours on your hands to build...and space. Lots of space to spread it all out. I'm fairly handy and it took a while. Do NOT use any electrical tools on this or you will break something. I anticipate this lasting about 3-5 years at most. If you are planning on moving this to a new location after it is built, it will likely not withstand the move.