What is the "Large field backpack" in the EOD edition?

I read through the benefits just now and realized that you get a "Large field backpack" by purchasing the EOD edition. Does anyone know if this is a unique backpack that can't be lost, such as the tomahawk or Gamma container? It doesn't say "unique" in the title, but it would be weird to list the backpack as a benefit by itself if it was NOT a unique backpack. Couldn't have this perk been included in the "Additional items in stash" benefit?