There was a major difference between the M2 and M2A1 - the former had a skate rail for AA machine guns fitted around the inner edge of the rear compartment, while the M2A1 eliminated the skate ring and had an M49 ring mount for a .50-cal machine gun located in a pulpit over the co-drivers seat. It also had three pintle mounts in the rear for a .30-cal machine gun. Either of these vehicles can be fully built up, since all necessary parts for both vehicles are included. Requires paint and glue (not included).