I' ve had leeches for quite awhile. They have been improved dramatically a couple times the last year. I think most dealers and mass merchants are not selling the new and improved stuff. If you want the best leeches buy the new " Stealth Leech" from Sims. They will last! I' m on 2500 shots with mine and no sign of wear. I got a pair from my dealer who got them from Sims before they were even on the market. They are out there now!

One tip for installation: don' t slide them into position when the string is at all tight. Ant friction from sliding them will dramatically shorten their life.