Application: For custom tanks, splash bowls, bottles etc Fuel Oil Tank /Fuel Surge Tank ,Water Tank , Radiator, Coolant ,Cooler. For use with fuel systems & any other applications. Specifics 100% Brand New. Aluminium screw filler cap neck for fitting to a hose. It can also be welded to a tank. The cap 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 most project. Including rear end differential housings Fill Caps, Valve Cover Fill Caps, Surge Tank Fill Caps, Coolant Overflow Catch Cans; And Just About Anything You Can Think Of. They Are Not Vented And Come In 3 Different Sizes, See Related Products in our store. Part Type: Coolant Reservoir Caps. Type: * Screw On Cap * Includes Sealing Ring Cap Material: 6061-T6 Aluminum alloy Cap Finish: Black /Silver same as the picture. Size : 1.5 -38mm (1.0"inch ), Neck ID - 24.5mm, Length including cap - 32mm 2 -49mm (2.0"inch ), Neck ID - 35.8mm, Length including cap - 32mm 2.5-60.5mm (2.5"inch ), Neck ID - 45.0mm, Length including cap - 35mm 3.0-78.8mm (3"inch ), Neck ID - 61.0mm, Length including cap - 35mm Note : For the size please check with the picture, and for the size 1" ,2" ,2.5" ,3" that's refer the tank's hole size . Profeional Installer is Highly Recommended (No Instruction Included).We are manufacturer, if you want other size , please contact us.thanks. All items are Brand New unle stated otherwise on the listing. We sell DIY (Do It Yourself) Items with a few exceptions. We take no responsibility in teaching you how to install. Profeional installation is strongly recommended.