Material 6061 aluminum alloy, anodized polished and for enhanced strength. Operation Principle: When the coolant pressure in the radiator exceeds the pressure cap setting, the coolant is sealed through the pressure cap and flows through the overflow tube into the radiator coolant overflow tank. Scope of Application: Great for containing coolant/water spills from the radiator. Also suitable for windshield washer fluid or intercooler containers. Includes: 1 Piece Water Coolant Expansion Tank and 3 adapter heads (15mm,11mm, 9mm) material Light weight and durability This is High quality of aluminum alloy material Easy installation, Excellent fitment and Superior Material Type:Coolant Radiator Water Tank Condition: Fitment Type:Direct Replacement Fitment:Universal Type Colour:Black Material:Aluminum Alloy Package Contents: 1 x Coolant Radiator Water Tank Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.