The secret behind the Slotted Kisser Button is the unique blend of materials that make up the kisser button. The material is soft while others are hard plastic. Hard plastic does not allow you to flex into position. With the Pine Ridge Archery softer, yet super-strong material, the kisser is flexible and more comfortable on the lip. The larger (11/16" - 17mm) diameter is great for the shooter who hunts with a facemack too. The "Slotted Kisser Buttons" are made of soft material, but they have the slit in the side allowing you to install the kisser without removing the string from the bow. These innovative designs can quickly be put on the string, saving archers and pro shops time. They are soft so they won't irritate the corner of the mouth and they look great. The Pine Ridge Archery Kisser Buttons also help eliminate bow string noise and squelch string vibration thanks to the soft, durable material they are molded from.