Two building challenges in 1 set - this cool Max-D 2 in 1 monster truck toy rebuilds into a pull-back quad bike for longer lasting playtimeDetails include Max-Ds authentic colours, spikes, movable flag, and a rough metallic surface with fire graphics just like on the real truckWith pull-back action, it's easy for kids to power their truck and quad bike; simply pull back and let go to send them speeding alongLEGO Technic universe offers a great introduction to engineering with detailed models, kids learn as they playFree LEGO Building Instructions app with Instructions PLUS is available, with zoom and rotate tools to help kids get building