I left the jack off to paint it off the model and add it late in the build. Here you build the jack and mount the road wheels. You add some detail to the rear plate and the sponson cover plates. Be sure to drill out the holes required for your build. Builds the upper part of the hull chassis. The fit is okay, but putty filler is still required to fill in the cracks. To fill the slot Meng has a piece to drop into the slot. Meng designed the arms with a slot to reduce the sink marks that occur with thick plastic parts. I suggest that you not glue in the idler wheel as you might want to remove the locating pin to allow the idler wheel to rotate to provide the correct tension to the tracks. You have a choice between 2 types of spring bump stops here. I would only leave these 2 parts off where the kit would be in a diorama that required something other than a flat road fit. Since there is no interior there were no torsion bars to give some lift, so the arms just flopped around. Without these 2 parts the suspension arms were too loose. I went back and added A4 and A39 to hold the suspension arms. I left this part off to see how the suspension acts without part A4. You need to decide if you want the suspension arms moveable or not. Builds the road wheels, drive sprocket and idler wheel.
It appears that it would replace part C13.
Not listed, but in the box was a metal barrel. This is kit comprised of about 600 styrene parts of which 508 are the track pieces, 2 frets of photo etched parts, an abundant set of poly caps and a set of braded wire for the tow cables.