ITEM NAME:4x One Way Non Return Check Valve 6mm & 10mm Aluminium Petrol Water Oil Fuel Description: The life of Aluminum head is longer than plastic head. Arrow marked on valve, showing fluid flow direction, Prevents fuel from returning back to the tank and keeps it in the line. Also great for water pressure pumps & galley pumps which are not self-priming. Professional grade non-return valve - for marine, automotive, caravans/RV, and agriculture. Easy installation and replacementï ¼Å’fit for Carburetors and low pressure fuel systems. Specification: Color: Silver Material: Aluminum Alloy Package Includes: 2 Pieces 6mm One Way Non-return Check Valves 2 Pieces 10mm One Way Non-return Check Valves Note: Please allow 0.5-1 inch difference due to manual measurement.(1 inch=2.54cm) Please check the size measurement and the picture carefully before making.The life of Aluminum head is longer than plastic head. Material: Aluminum Alloy.