He is using a double wide colony trap and yes it has 4 doors. I make and use them in rigid and folding with or without bitebars, 24 to 30 inches long, 5x10 to 8x16, and with or without wings.
3nails are you using the design that Dave Vinke came up with? If you are put 2" bite bars at the end of the dividers and that will help keep the rats off the doors.