I want to point out a couple of differences between the K4 and the K5, and why I chose the K5.
Few things here. On the back side with the red arrow is the release button to adjust for the thickness of the stock. Pushing down on the gray button, releases if from the teeth, (yellow arrow), and then the clamp slides in or out to get you close.
The red circle is for the final clamping of the stock. Just a push on the lever and the stock is nice and tight. Once the stock is in place, you drill the holes.
Clamping, unclamping and drilling are all done from the same side.
