The kits have there own re-coil unit that plugs into the MFU (Muliti-Function Unit) along with the traverse,gun elevation, and speaker. Go to this site. It is the Manual for the Tamiya 1/16 Panther G. Scroll through it and you will get an idea of how the Tamiya tanks go together before you buy one.

http://www.tamiyausa.com/pdf/manuals/56022ml.pdf