The Tellermine 35 (T.Mi.35) was a German metal cased anti-tank mine used extensively during the Second World War. The mine's case is made of sheet steel, and has a slightly convex pressure plate on the top surface with a central fuze well. Two secondary fuze wells are located on the side and bottom of the mine for anti-handling devices. For use on beaches and underwater the mine could be deployed inside a specially designed earthenware or concrete pot, which acted as a waterproof jacket for the mine. Pressure of 400 pounds (180 kg) on the center of the mine or 200 pounds (90 kg) on its edge deforms the pressure plate compressing a spring, and breaking a shear pin which holds back the spring-loaded striker. Once the striker is released it flips downwards into a percussion cap which fires the adjacent detonator followed by the booster charge and then the main explosive filling of TNT.