This Military Crew consists of the X78, the X78/B and the X79. These guys are sporting some of the best power armor out there. The X78 is a larger hard suit, perfect for tanking, that accommodates a Minifigure sitting down. Outfitted with a large rifle this guy is ready to fight. The X79 is the smaller armor, which makes it much more nimble. This power armor comes with rocket launchers and an automatic weapon. Finally the X78/B is an alternate version of the X78. This time accommodating a standing position, and a little bit more armor. These three Military Troopers are the work of Devid VII. Who shows off some excellent Minifigure scale building techniques. Check out how the standard legs are removed and the power armor is incorporated into the torso. Allowing a more realistic appearance (knees!)
Check out the Military Troopers X78, X78/B and X79 over on Flickr: https://www.flickr.com/photos/devid7/16020152777/
You can also find a whole lot of Lego robots, mechs, and hard suits over here: http://everydaybricks.com/category/robots-2/