The Blue Snap-On Reeds fit the Terminator the Pack Bugle and the Bull Horn. Blue Snap-On Reeds are molded from silicone. Silicone wont rot like latex and theyre easy to usejust snap em on and youre ready to go. Theres no stretching or frustration trying to tune your call. - Pretuned! No adjustment needed - Unlike latex reeds Primos silicone reeds can last an entire season