This second version of the S-Mine had quite some important differences. The mine only had 3 plugs on the top. One for a fuze (or adapter), a filling hole and a hole for 1 detonator, instead of 3. The other change is on the inside at the base. Instead of 3 delay pellets, there is a steel wire fixed to the base of the outer shell, securing a small pre-cocked firing pin with the other end of the wire. When the mine was driven upwarts, the steel wire would pull the pin, firing the detonator-and mine.
When a vehicle passed over this mine the bursting charge would ignite, but the pressure would keep the mine down, unexploded.

Picture on the right shows the two types of S-Mines next to eachother.

Shown below are some nice markings on a SMi.44.

Photo below Dieter.