I never used one since I shot fingers, Then started using a release so I put one on. Took my bow to have a new string put on and (I' ll call him my friend ) the pro at the shop didn' t put one back. When I enquired about it I was told that I would be better off without it and would only have to replace the serving periodicaly. And I' ll be darned he was right. Works for me I hope it works for you. I guess to each their own,plus I think it adds about 2-3 fps without one. Ps haven' t the need to replace the serving yet.