Didn’t know it existed !!!! Very happy with the purchase!!!

There's a booklet for written instructions, but no visual instructions or even a video to show how to properly use it. Not sure if its working well yet because of the awkward hap at the end.

Difficult to use, but after practice gets easier to use. Needs suggestions or instructions to insure success.

Makes sharpening your knives almost fool proof. Just make sure to have good whetstones.

Will be a great asset to control the angle of the sharpening stone to knife blade.