The Death Enderchest is a unique Enderchest featured in Advanced Genetics. It only functions if the player has the "Inventory Retention" ability taken from an Enderman. When the Death Enderchest is placed in the world, the player must right-click it to link the Death Enderchest to their inventory.
Upon the player's death, their whole inventory will be transported to the Death Enderchest, allowing the player to collect their items whenever they like without fear of the latter despawning, provided that the player has the ability mentioned above and has linked their inventory to the chest.
The chest can only be broken by shift-right-clicking with an empty hand or broken normally if in Creative mode.