This device consists of a spring-loaded firing pin which is designed to be released when the accessory under which it is fitted is removed. When the mine is dropped, im-pact with the surface causes a lock ball to fall away, leaving the firing pin restrained only by its extensior arm, as shown in figure 305. If the accessory is withdrawn 0.6 inch, the extension arm moves clear of the body of the accessory, releasing the firing pin to im-pinge on a special detonator, firing the main charge.

This device was originally designed to be fitted under bomb fuzes, and its use in mines is thereby restricted by its basic design to mines Type LMB, LMA, and BM 1000, the only mines that have contained bomb fuzes. It should be noted, however, that this device may be used under any fitting, the physical construction of which would permit effective operation.

Figure 305 – ZUS-40 Anti-Withdrawal Device