MM,
I just got the Spring Turkey Catalog myself and spent a great deal of time scanning it myself. That "knob" I believe is for a new drive system that lets you adjust the sight from the "back end". I forget what the catchy term for it is in the description but it sounds kind of cool.
I must have missed the term "Guide Series sights" but I did see the TR Guide Dropzone rest.
Anyone else notice that Parker is now offering their bows through Cabelas? I thought they were pro shop only???
...and that new limb vibration dampener from NAP looked rather intriguing as well.