If you stretch a piece of peep tubing over the leech' s center and then install it they will last much, much longer. I haven' t had to replace mine yet and they' ve been on my string for 3 years -- approx. 2000 shots per year. I' m shooting a Mathews FX @ 70 lbs & 29" . If you try that method I' m sure you' ll see that it works.