Universal Parts 57.4mm Stock Cylinder Head Gasket Kit for 150cc GY6 4-stroke engines. Includes base, head, exhaust, intake, and timing chain tensioner gaskets. Diagonal Bolt Hole Spacing: 76mmBase Ga sket Inner Diameter: 62.5mmHead Gasket Inner Diameter: 59mmTiming Tensioner Gasket Inner Diameter: 2 Universal Parts 57.4mm Stock Cylinder Head Gasket Kit for 150cc GY6 4-stroke engines. Includes base, head, exhaust, intake, and timing chain tensioner gaskets.