Features: Aluminium screw filler caps neck for fitting to a hose. It can also be welded to a for tank. The caps has a knurled outer edge for grip when unscrewing and is supplied with a sealing ring. 6061 billet aluminum bung and caps are great for just about any project. Perfect match for the car. Compact size and lightweight. Easy for apply and use. Easy installation. Package Includes: 1x Radiator Water for Tank Caps Specifications: Material:Aluminum Size:Approx.3.7cm/1.45inch Size:Approx.5cm/1.96inch Size:Approx.6cm/2.36inch Size:Approx.9cm/3.54inch Color:Black note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings.