Compact fourstroke singlecylinder engine model for middle school physics experiments. This readytouse demonstration model shows the basic structure and working principle of a fourstroke singlecylinder engine with clear, visible moving parts. Its compact, preassembled design saves setup time and keeps attention on learning. Key benefits Clear demonstration of engine operation: Illustrates intake, compression, power, and exhaust strokes so students can see how a fourstroke engine works. Ready for classroom use: Preassembled and easy to operate, allowing teachers to start demonstrations immediately without tools or setup steps. Flexible power options: Operate manually for close inspection or power the model using 2 x 1.5V AA batteries, not included, for continuous motion during lessons. Durable construction: Built from plastic and metal to balance durability and visibility while remaining lightweight and portable. Compact and portable: Small footprint makes it easy to move between classrooms or place on a demonstration table. Specifications Material: Plastic and metal Power: 2 x 1.5V AA battery required for powered operation, batteries not included Base length: Approx. 17 cm Width: Approx. 11 cm Height: Approx. 30.5 cm Weight: Approx. 766 g Package includes: 1 engine model Size details: See product images for visual reference Typical classroom applications Middle school physics lab: Use during lessons on thermodynamics, motion, or mechanical systems to connect theory with a visible mechanism. STEM activities and projects: Integrate into group projects to help students investigate how engine components interact and sequence through the four strokes. Teacher demonstrations and science fairs: Use the manual or battery mode to show realtime motion and engage student questions during presentations. What makes this model practical for educators No assembly required saves class time and reduces setup errors. Dual operation modes let instructors choose handson exploration or continuous demonstration. Compact size and low weight make storage and transport simple for multiroom use. This engine model is designed to be a reliable classroom tool for explaining engine basics and supporting handson STEM learning.