Description: 100% Brand new and high quality. It is durable and convenient. Easy installation High Performance Upgrade Cylinder Rebuild Kit for GY6 50cc engine Intake Valve 18mm, Exhaust Valve 16mm Package Includes: 1 Set Cylinder Head Assembly 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 payment