The Swingbyte mounting tab is an optional attachment mechanism that helps ensure that you attach your Swingbyte the same way between sessions, and helps prevent your Swingbyte from rotating about the club shaft from severe impacts.
To install, first attach your Swingbyte in the correct way - at the 3 o'clock position for right handed golfers, 9 o'clock for left handed golfers. Make sure the gray seam on the back of your Swingbyte is lined up as well as possible with the leading edge of the club.
Next, make a mark (with a pen, or marker; if you want to avoid leaving a permanent mark on your grip, place some painters tape over it, then remove it later) on the grip, directly where the crosshair on the Swingbyte is pointing. Remove the Swingbyte.
Finally, remove the wax paper from the mounting tab, and place it on the club shaft, just below the grip, with the peak of the crease on the tab aligned with the mark you made.