Fuel supply line – runs from tank to engine. Fuel return line – runs from tank to engine. Professional installation is recommended. We accept order cancellation for any reason within 30 days of receiving your goods. Please take considerate care of the goods and return it to us in its original condition which is required for a return eligibility. All products are subject to availability and may be withdrawn at any time. In the event the item should fail due to manufacturing defects during intended use, we will replace the part by free. Hours of receipt or sooner.