Photograph of bins on the outside wall of Dachau gas chamber where Zyklon B pellets were poured onto floor of gas chamber

Outside wall of gas chamber has two bins for pouring in Zyklon B gas pellets

Zyklon B pellets produce poisonous cyanide gas when heated, although there is no heating device used in the Baracke X gas chamber. The bins have hinges on the bottom so that they can be opened or closed. The rectangular hole in the wall is covered by a piece of wood, and there is no corresponding hole inside the gas chamber.