there have fixed screw hole in the hull. you need DIY for your PCB, such as Arduino,etc
on the buttom, have an battery space not battery box, it can put 6 pcs AA battery. you can clear for the photo.
we have spare track and acrylic plate for sale, if you need, you can buy from here http://www.ebay.com/itm/robot-tank-chassis-track-Crawler-1-pics-for-SN200-SN201-SN300-/272082723808?hash=item3f5964e3e0:g:1EgAAOSw~bFWJz7J
the photo of below just for demonstrate not incloud for this product