Known as "The Shu Mine" (for their activation by a soldier boot or shoe), was a German anti-personnel explosive device, designed and deployed between 1942 and 1945. The "Shu" was a unique weapon, in that the explosive case in which the mechanism was stored waso made of wood. This defeated measures to locate the mines with traditional metal detectors.
Pressure activated (spring loaded), they were square boxes buried in up to 4-inches of earth. The devices contained 7 ounces of shaped TNT plastic explosive. Once pressure was applied to the top, a firing pin and ignition charge was driven into the shape charge, triggering an explosion. Capable of severing an entire leg or foot, The Shu was very effective as an anti-personnel weapon.