Although it was originally designed as a Schartenbrecher ("bunker buster") for use against the French Maginot Line defences,[1] following the defeat of France in 1940, it was evaluated for use as a tank destroyer on the Eastern Front.

Similarly the ammunition bins holding 26 rounds for the main gun had thin armored covers on top.

Another oddity was the fake driver's compartment on the right side of the vehicle that matched the real one projecting forward from the front superstructure on the left.

Although the main gun was intended to engage enemy armoured fighting vehicles it could only traverse 8° to the left and right, depress 15° and elevate 10°.

periscope was fitted for use by the commander, and each loader was provided with a binocular Scherenfernrohr on a pivoting arm.

Production vehicles probably would have used the suspension and running gear of the Panzerkampfwagen III as it offered increased maneuverability due to a shorter length of track in contact with the ground, less rolling resistance, softer springs and greater deflection of the suspension.

[3] For combat trials the two prototypes were assigned to Panzerjäger Abteilung ("Anti-tank Battalion") 521 during the invasion of the Soviet Union.

One accidentally caught fire and was completely destroyed by the detonation of its ammunition, but the other fought successfully until the end of 1941.

It was rebuilt by Krupp during the first half of 1942 and returned to the 521st in time to participate in Case Blue, the 1942 summer offensive in Russia.

In addition, because of its armor layout - only thick in the front and 50 mm lower in the back - it was built for frontal use.

Because of its size, lack of mobility, and large dust cloud raised when firing, in the future the Sfl.