There are several different guides to achieve a defined cutting edge angle.
Here is an example of a no-name aid. Here you have the problem that you must take care of the correct bevel angle yourself. The jaws automatically ensure the correct transverse angle during clamping (if they are precise).
Fig: The NoName Guide
The luxury model for guided tours is apparently the one from Veritas. It is not exactly cheap, but you also get an adjustment aid for the length and thus for the cutting edge angle. The transverse angle is also controlled via the length stop. There is also a simple setting for a micro bevel.
Fig: The Veritas guide without length stop
Fig: The Veritas guide without length stop
Fig: The angle setting of the no-name guide (just off)
Fig: The fastest way to set the angle, for Veritas and the no-name guide