This is a physical product to coincide with Brickmania Digital Building Instructions for the K2 Black Panther - Main Battle Tank! This product includes 30x (15x Green, 15x Brown) custom 3D printed Brickmania tank wheels. Brickmania custom 3D elements add an extra level of functionality and detail to your build. So whether you're creating one build, or several, Brickmania custom elements will bring your builds to life!