first time buying a sharping stone. i bought this because i wanted to sharpen kitchen knives. you have to practice to get good at it, use a knife you don't care about because you might mess it up. there is some conflicting instructions online on how to use, water or no water. read as much as you can about using stones and practice, practice , practice. look up videos on youtube and internet. i had fun using it, BUY IF YOU WANT TO LEARN here is some stuff i found, they all sound like professionals this is a video that says don't use water this is a youtube video that i watched that uses water. *informative
As you continue to repeat strokes on the first time, eventually a tiny burr will form on the other side of the blade. To check for it, place the blade on your thumb, and pull it backwards. If the burr has formed, it should catch slightly on your thumb (with really fine grit stones, say 2000 or above, you won't feel this). This may take up to 30 or 40 strokes, and is the indication that you should switch and start sharpening the other side.

Unfortunately, the arrays of modern whetstone can be bewildering to the inexperienced sharpeners that so often times many of them end up with a crap or wrong decision on stone type for their utensils. The most difficult to determine is whether the whetstone is fake or fabricated with low quality of materials. To avoid this you can only go for the reliable brand of a whetstone.
if you have regular kitchen knives it will not work- first its to deep and the blade does not stick out, not dinner knives but cooking knives. of all the knives i put in it only 1 was wide enough to stick out. the device does not hold the blades. all the blades tested fell out of it, even a hunting knife, maybe its for 1 type of knife and they are selling it as the must have tool for all.. that said sell something useless for a few bucks that most cant use, they got a few bucks that most will blow off and not worry about a refund.. DONT WASTE YOUR MONEY.
The kind of tech we love: compact, reliable, durable, attractive and cheap. Purists may feel that other sharpeners will produce a more perfect result but for 99% of the human race this sharpener will be everything the doctor ordered. Your blades stay sharp for a good long time thanks to the 2-stage sharpening process and if you’re a left handed chef you’ll love the fact that it works just as effectively for you as for anyone else.
In addition, the most prized of the natural Japanese Water Stones are quarried in the Narutaki District north of Kyoto, Japan and are commonly available as either bench stones or pocket stones in grits ranging from 120 to 12,000. On the other hand, synthetic water stones are made from Aluminum Oxide and commonly available as either bench stones or pocket stones as well in grits ranging from 220 to 8,000 and, although this is the same abrasive material used to make India Oil Stones, the difference between the two is that the binder that holds the abrasive together enables Water Stones to be much softer than India Oil Stones which, in turn, promotes faster cutting because the worn abrasive material breaks away more quickly and is replaced with fresh, sharp, abrasive material more quickly. In addition, because water stones do not become glazed or loaded with swarf like oil stones can, new abrasive particles are constantly exposed as the stone wears so it continues to cut consistently. Plus, they can be lubricated effectively with water (rather than oil which can ruin some water stones) which combines with the fine particles of abrasive from the surface of the stone to form a slurry which polishes the bevel as the stone cuts. However, it should also be noted that Water Stones do become uneven significantly faster than other types of whetstones although, their softness does make them easier to true again.