Push-back racks are also called press-in racks, which are composed of beam racks, rails, and trolleys. The trolley adopts a nested arrangement to run on a track with a set oblique angle. The goods entering later will be pushed into the goods first. When picking up the goods, the outermost pallet will be taken first. When the outer goods are taken out, the inner goods will automatically slide down by gravity. Realize first-in-last-out storage.