Battle Droid (Commander), or OOM command battle droid, was a battle droid used by the Trade Federation and the Confederacy of Independent Systems. They are considered the leaders of a certain amount of battle droids and are ranked officers in the Separatist Army. This was in the Prequel Trilogy. There is a version with a partially yellow chest and one with an entirely yellow chest. In the Lego Star Wars video game, it can use walkie-talkies by responding with a "roger-roger".