The DLC consists:
1.Digital Artbook"Art of Alien Marauder"
2.Exclusive 4K Wallpapers
3.Special outfit(Skin)pack

The battle rages on, and our expedition is just beginning. Behind the sceneries swarming with walls of guns and tides of claws, there's a history of people working on visual designs, concept art, and all inspirations needed, bringing it to life.
See how our creativity comes into shape with concept arts reflecting different stages of development. The book features technical drawings and artwork from our wonderful art team. Alongside with different side notes showcasing statics, origins, lore, and other interesting facts, unveiling a new space frontier in an in-universe perspective.
The Special outfit pack consists special skins for three kinds of survival mode defence towers:Silent Tower, Flame Tower and Ion Cannon.

Instructions on DLC contents

1.Where can I find my Artbook and Wallpapers?
The Artbook and Wallpapers will be placed in your Field Manual folder once your purchase of Alien Marauder-Field Manual DLC is complete. Right click on "Alien Marauder" in your steam library page, then select “Manage”-“Browse local files”to find the folder.
2.How to use the Special outfit (Skin) pack in game?
Select "Armory" in the in-game main page, then select "Skins" to check and use the purchased skins.