 The multiple safety/arming features in the M734 mortar fuze are representative of the sophistication of modern electronic fuzes.Safety/arming mechanisms can be as simple as the spring-loaded safety levers on M67 or RGD-5 grenade fuzes, which will not initiate the explosive train so long as the pin is kept in the grenade, or the safety lever is held down on a pinless grenade.Alternatively, it can be as complex as the electronic timer-countdown on an influence sea mine, which gives the vessel laying it sufficient time to move out of the blast zone before the magnetic or acoustic sensors are fully activated.