7713-1 (Inv) Bridge Walker vs. White Lightning 632 Parts, 4 Minifigures, 2006 Sets: Exo-Force
* Add 1 Part 57029c01 Black Projectile Launcher, Cannon, Flat Bottom (Alternate) (match ID 28)
Comments from Submitter:
I discovered the projectile launcher I have on mine is the flat type (wich was introduced the exact same year, 2006). I bought this set on release and never disassembled it, I am 100% sure this is another alternate for this set.