Takegawa titanium valve adjusting retainer nut is now available for CRF50, KLX110, CRF70, CRF100, NSF100, and most import Chinese manufactured engines from Pitster Pro, Daytona, YX, Lifan, Jialing, and Zongshen. For use on stock cylinder heads as well as R-Stage +R Superhead, 4 valve Superhead, Ultra SE and Ultra SE Pro.