Canton coolant expansion fill tanks are manufactured from .100 Inch thick aluminium. These tanks have billet aluminium necks which feature a barbed overflow fitting. The design of these expansion tanks means that they accept a standard radiator cap. You will need to use an expansion tank in any system where the top of the radiator is below the top of the engine. Expansion tanks provide an air space for the coolant to expand into. When mounting the Canton coolant expansion fill tank you should make sure they are higher than the engine and radiator to ensure both are entirely filled. The tank itself should be partly filled, this leaves space for expansion.1 1/4 Quart or 2 Quart options with 3/8" NPT side port and 1/2" NPT bottom port.Includes: Aluminium Construction Billet Aluminium Neck Barbed overflow fitting Standard radiator cap fitment Built-in brackets Overflow hose Dimensions:1 1/4 Quart = 5 1/2" Tall, 4 1/2" Wide, 3 " Deep2 Quart = 8" Tall, 5" Wide, 4" Deep