Strawbees Inventor Builder Kit - 150 Straws and 250 Connectors Set, Educational & Creative Building Toy, Tinkering & STEM Learning, Suitable for Children 5 Years & Up Time to go Pro  The Inventor kit is our second biggest kit perfect for testing more advanced creations. It features 400 pieces, an instructions manual with 21 fun maker projects. Create a bird, a huge mechanical snake, or a replica of the pyramids of Giza. Enough pieces to start inventing really cool stuff or building with your friends.