Wooden Puzzle Model Car Kit Electric 2 Way Science and Technology Simulation Tank with Remote Control Item Type: Remote control God of War tank model car Material: Composite Wood, ABS Use: Handmade, Educational Teaching Paint Material: Original Wood Without Paint Wooden Block Type: Building Blocks Remote Control Vehicle Power Supply: AA Battery x 3 ( Shipped Without Battery ) Remote Control Power Supply: AAA Battery x 2 ( Shipped Without Battery ) Remote Control Distance: Approx. 30m/98.4ft Scientific Principle The wheels of the tank are divided into three kinds: drive wheels, guide wheels and load wheels. The driving wheel is responsible for providing power, its characteristic is that it is the only one with teeth among all the wheels, it is directly connected to the gearbox, only responsible for rotating the tracks, that is, this wheel determines the speed of the tracks, as far as the position is concerned, it should be the most forward or the most backward wheel of the whole tracks, it is on the top of the two rows of wheels, and it doesn't bear the weight of the vehicle body at all.