3.5" Can with Jiffy Tight Fittings, 36 lb. PRV and Gauge Assembly. With the C&R pressurized cooling system, the engine can safely operate at higher temperatures for a longer period of time. By utilizing the functionality of the air spring in the pressure can, there is less chance of overheating due to rubber and oil dry build-up. You can run leaner for power and not be in danger of overheating. With today's technology, a pressurized cooling system is more efficient and failsafe than the customary closed cooling systems.