All OEM Yamaha Parts. Flugelhorn (YFH-631) valve tune-up kit. 3 each guides, guide washers (metal), springs, valve stem & top cap felt washers. Includes 2 valve slide Orings & 3 water key corks. If in doubt, email me with your model. Please note Yamaha YFH-635; YFH-6310Z, YFH-8310; YFH-8315 use a smaller spring.