Explore functioning air compressors, pneumatic valves and cylinders with this hands-on kit. Includes a compact and powerful compressor to supply compressed air to the models. Build eight different working models: double sliding doors, scissor lift, catapult, balloon pump, tree trunk gripper, hay bale picker, front loader and excavator. Includes a comprehensive instruction manual with background information and teaching suggestions. A 9 V battery is required and available separately.