 The grid is held in place by a thin metal wall.Sufficient pressure on the grid causes the wall to collapse sideways, allowing the grid to press down on a plunger triggering a 3.5 oz (0.1 kg) Toul (Tetryl)  booster charge, detonating the mine.The mine can be fitted with two main fuzes, the RO-5 and the RO-9 fuse.