Description: DIY Material Kit: Balloon powered cars DIY toys need to be assembled by kids themselves, exercise children's hand eye coordination and creativity Educational Science Toys: With a simple experimental setup, students can quickly understand the reverse thrust and reaction force of physics Ability Development: STEM wooden toy good for kids manual brain, training, intellectual development, parent child communication, interactive toys Science Toy for Kids: Wooden model car kit, to exploring and learn the scientific knowledge Great Gift: DIY science educational crafts gift is for kids on birthday or parties Specification: Material: Wood, PP Size Chart: about 11.5cmx6.6cmx5.7cm/4.53inchx2.60inchx2.24inch (After assembly) Package Includes: 1 Set Children DIY Kit(Unassembled)(6 Pack) Note: 1.This is not infant toy, please take away from children to avoid eating. 2.Please allow slightly errors due to manual measurement and different monitors.