| Feature | Description | | :--- | :--- | | | 24x24 or 48x48 divisions (pre-creased grid). | | Unit Pattern | Alternating mountain and valley folds forming a zigzag. | | Movement | Radial expansion (push ends → ball inflates; pull → collapses flat). | | Material | Thin, strong paper (e.g., Kraft, foil, or baking parchment). |