The OPOC two-stroke engine developed by EcoMotors uses two opposing pistons within each cylinder that move in opposite directions. This design allows for increased efficiency over conventional two-stroke engines by enabling precise computerized control and reducing the number of parts. The OPOC engine provides advantages like higher power-to-weight ratio, ability to run on different fuels, and potential 45% increase in fuel efficiency when using multiple electrically-controlled engine modules. The key differences between OPOC and common two-stroke engines are the use of two pistons per cylinder instead of one and sensors/electrical components required for computerized control.