Power Tools has been developing a new series of electrical stone-breaking cartridges for a long time, and the development has passed from cartridges with integrated igniters to a wholly new series of Simplex cartridges with separate igniters, to be used for breaking stones and rock. We regard it as obvious that cartridges should be transported and handled without the igniter inserted in them, just as dynamite is not transported after the igniter has been inserted. Using separate igniters gives the user greater safety and higher power, while satisfying future demands for rock and stone breaking. Another clear advantage of using a separate igniter is the ability to choose between Class 2 and the slower Class 3 igniters for the cartridge. This was not possible with our earlier cartridges with integrated igniters.