From: http://www.geocities.com/Athens/Acropolis/8141/halftracks.html
The SdKfz 7 was the most numerous of the Zugmaschinen of the German forces. Originally designed to haul the old 75mm cannon it added decisive weight in North Africa and the Eastern Front by giving mobility to the dreaded German 88mm Flak. Other varients included self-propelled mounts for quad 20mm or a single 37mm Flak gun, a light-tank hauler, an anti-aircraft detection vehicle and a command vehicle for the firing of V2 rockets.
In 1934 design work was started on the Type 1934 powered by a 115PS Maybach HL 52 gasoline engine. In 1938 three firms started producing the first type: the 'KM m 8' by Krauss-Maffei AG, Munich, the 'DB m 8' by Daimler-Benz and the 'BN m 8' by Bussing-NAG. In 1939 the 'KM m 9' with a Maybach HL 57 engine was produced as a hauler for the s.FH 18, the s. 10cm Kanone 18, and the 88mm Flak. The next type 'KM m 10' was
the same as previous versions but with a 140PS Maybach HL 62 TUK engine. The last type 'KM m 11', with minor changes, was produced from 1939-1944.
Total weight was 11 tons, hauling capacity 8 tons with a crew of 11. Total production was 12,000 units.
Google has a lot.