Looking to make a fast, economical repair on an aluminum air conditioning, coolant, transmission, oil or fuel line? 4Lifetimes' 5/16" Repair Union - Aluminium to Aluminum can help. This product quickly and easily fixes pinhole leaks, cracks and kinks without any welding or soldering required. It is airtight and pressure resistant up to 2000 PSI which makes it suitable for high-pressure applications such as transmission cooler lines, steel fuel lines and more. With this product you can conveniently repair automotive and heavy duty truck applications in no time!