How can we tell the difference?
Balanced Cylinders have a shaft extending from both ends of the cylinder. It uses the exact same amount of fluid to turn in both directions.
Unbalanced Cylinders have a shaft extending from only one end of the cylinder and requires less fluid to steer the engine/rudder in one direction than the other.

If you join two unbalanced cylinders opposing each other then they function like a balanced cylinder.

If the steering system is unbalanced depending on the pump you may need to purchase an unbalanced kit.