This Robotime Bi-Plane Puzzle Kit offers a fun and educational activity that will give you a sense of accomplishment. This kit is an iconic image of aerospace engineering and a project that you can build on your own. Put all the pieces together, and watch the gear unit move the pieces. You do not need glue or other tools. Just follow the step-by-step instructions in the instruction manual. This is a great STEM activity for ages 8+. 145 pre-cut pieces of wood with an approximate assembly time of 1-2 hours.