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I would put cat whiskers and serve them on as close to the outer limb ends as possible. You can try some limb savers, they work. Then there is heavier arrows. The only problem with things you put on the string is that sooner or later they come off and some times into your face. The limb savers are more affective closer to the outer ends but really slow down the bow just like most string silencers. Heavier arrows are work really well. But the most effective silencers are like Dan said,,,, ear plugs. You don't need a quiet bow to kill deer at ethetical distances period! Silencing a bow is for the shooter because the deer will hear it when its too late.