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.

The ribbed case stopped sand from blowing off the top of the mine when it was used in a desert or sandy environment.

Pressure of 400 pounds (180 kg) on the center of the mine or 200 pounds (91 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.