I saw this little device and to be fair, I was highly dubious that would work.
I have spent a lot of time soaking stones and sharpening shears etc.
Read some reviews and thought I would give it a try,
I was so wrong.
I gave it a test to get the hang of it, on some ancient shears I use for cutting the odd bit of grass. A few stripes with this and they sharpened up amazingly.
Counterintuitively, it it the edge of the mirrored side, that does the sharpening and the grooved side that does the fine honing.
I have sharpened two pairs of shears a pair of scissors and 4 pairs of secateurs with it. They came out very well.
I am going to try it on my lawnmower next, as because of its compact size. I should be able to do this, without removing the blade from the mower.
Be careful to make sure you have the correct angle when sharpening anything (follow the one the tool manufacturer put there as closely as you can) as this little tool, is surprisingly effective. You do not need to use a lot of pressure when using.
Get the correct angle and two or three stripes along the blade might well be enough.
I have tried to upload a video, giving a rough guide on how to use it and also and explanation of some issues, that seemed to be causing a problem, for some users, regarding the cap either not fitting or being too tight.
In the video I hold the secateurs with the point towards me, so people can see what I am doing more clearly.
Where possible, point sharp tools away from yourself (shears, scissors, knives etc).
Safety should be your first concern when sharpening.
Another tip, is to try this sharpening tool on an old pair of secateurs or scissors, till you get the hang of keeping the angle that was put there during manufacturing.
Start with slow light strokes and gradually increase to medium pressure, when you are more confident in your technique.
It is not very difficult but there is a slight knack to it.
If you get a little ridge on the back of the blade after sharpening (known as a burr) you can place the honing side of the sharpening tool flat against the back of the blade and one swipe should remove it.
Look up YouTube for removing burrs from tools, if you are not really sure what they are.