100 PzKpfw III Ausf M were converted from February to April 1943 by Wegmann Waggonfabrik in Kassel. The main gun was replaced by an oil projector 1,500 mm long and 140 mm in diameter. Two oil tanks (225 gallons/1,000 liters) with an auxiliary engine were installed in the hull. The flamethrower could be used about 70 to 80 times with 2 - 3 second burts. The range was about 65 yards.
A MG 34 was installed in the hull and one coaxially in turret. 30 mm of additional armor plate was added. The crew consisted of the driver, radio operator, and commander. The commander was alone in the turret.
The flamethrower was installed by Wegmann, Kassel.