Automail is a form of mechanical prosthesis of a somewhat steampunk style of design. Automail limbs are a common sight in the anime/manga series Fullmetal Alchemist, used by individuals who have lost limbs due to accidents or conflicts. These mechanical limbs are created by specialist engineers and blacksmiths who also practice surgical medicine, who design the limbs based on the needs of the recipients. Automail surgery is a lengthy and extremely painful procedure that requires the prosthetic's harness to be linked directly to the recipient's individual nerves so that the electrical impulses of the nervous system provide power to the limb, allowing the user to move it fluidly like a natural limb. First-time recipients of automail usually have to endure a long period of recovery from the procedure and practice with controlling the new limb before they are able to resume their normal day-to-day lives.
Automail can be customized to incorporate various tools that users would need in their chosen professions. In the militant country of Amestris, a number of its soldiers have had their automail modified for combat by outfitting them with weapons such as knives and firearms. In the 2003 Fullmetal Alchemist anime, it has also been shown that individuals can be outfitted with "full body" automail, having limbs and even internal organs supplemented with technology, becoming true cyborgs.