This Gasket is manufactured in-house to exceptional tolerances. All gaskets are made from scanned vector-mapped images of the OE casing to ensure an exact fit, the gasket material is high-quality BS7531 GRADE X with a working temperature of up to 250 degrees centigrade. This gasket is manufactured to replace the original part number 31140-422-610. This fits all CBX with the smaller style alternator. The diameter of the Euro alternator is 140mm so you can identify your alternator by measuring this diameter.