Yamaha YFH-631 Flugelhorn Valve Guides, nylon, no metal. Fits the following Alto Horns, Baritone, and Flugelhorns:
P/N F0141099
YAH-100S
YAH-202
YAH-202S
YAH-601ST
YAH-601T
YBH-100S
YBH-201
YBH-301
YBH-301M
YBH-301MS
YBH-301S
YBH-621
YBH-621S
YFH-631
YFH-6310Z
YFH-6310ZG
YFH-6310ZGL
YFH-6310ZS
YFH-631G
YFH-631GS
YFH-635ST
YFH-635T
YFH-8310Z
YFH-8310ZS
YFH-8315G
YFH-8315GS