To follow up on Tom's post, here are some photos of the two halftracks:
sdkfz-7.jpg
An 8 ton SdKfz 7 leading a convoy of Opel tucks heading toward Kovel. In this case it is compacting the mud to help the trucks pass. It also was used to pull these lighter trucks out of the mud.
famo.jpg
This is a FAMO, or SdKfz 9. It also came as the 9/1 with the 6 ton crane, and the 9/2 with the 10 ton rotary crane.