The SWTC over at TheForce.net seem to think there are two different variants...ATST and ATST/Assault...
http://www.theforce.net/swtc/walkers.html#atstas
The SWTC over at TheForce.net seem to think there are two different variants...ATST and ATST/Assault...
http://www.theforce.net/swtc/walkers.html#atstas