I split the original model from MakerBot since it was too large for my printer.
1 x Top
1 x Bottom
2 x Connector
Unless you have a printer with a very large print area, you will probably need to put the top part at an angle, so you can take advantage of the z-axis space.
The connectors are for the two holes in each part, in some cases they fit so tight that no glue is needed, but even if using glue, they help keep the parts aligned while the glue dries.
I recommend gluing the parts for maximum strength.