Cost – While you can get a perfectly serviceable sharpening stick or stone sharpener for short money and some very high-quality tabletop manual 2 and 3-stage sharpeners for less than $50, high-quality mechanical systems will often run you $200 or even more. While that’s not so much money it’s likely to impact the quality of your life it is a lot to pay to keep a decent edge on your knives. While how much you ultimately pay for a sharpener is entirely up to you, you may want to consider your commitment to cooking and how often you are actually liable to use the device. If this is your first sharpener you might also want to consider learning how to sharpen a blade using a classic stick or stone sharpener first, before deciding if moving up to a mechanical sharpener is the right thing for you.
I can personally verify that this will get your knives very sharp. I will spare you all the gory details, but the picture is of the instructions the ER sent me home with after stopping the bleeding and patching me up. I have to say, that’s not what I had in mind regarding “Thanksgiving tips”. So: not only will knives slide easily through spinach, but they will go through finger and fingernail like a hot knife through butter after being sharpened by this whetstone. Very clean, straight cut. Impressive, really. Just take it slow and don’t be a moron like me.
"How do I use this daunting metal rod?" I hear you ask. Well, it's not too hard, really. The best way for a beginner is to balance the steel on a surface with the tip secured by a damp tea towel. You want to get that angle right, whether it's around 15 degrees for a Japanese knife or 20 degrees on a German or French blade. Then swipe slowly down, away from you, making sure the whole blade is honed – around five swipes on each side should do. 
If you wish, further polish or even strop the edge to the desired sharpness. This makes the edge better suited for "push cutting" (cutting directly into materials, pushing straight down without sliding the blade across the object) but generally impairs slicing ability: without the "microscopic serrations" left by grinding with a stone, the blade tends to not bite into things like tomato skins.

I enjoy these stones so much that the feedback is not a deterrent at all for me, I don’t even think about it. The results are always nothing but top notch, they deliver exactly what I want, some of the sharpest knives I have ever produced were sharpened on Shapton Glass stones. They may be thinner but they last a very long time, they are easy to maintain as well, 

The whetstone is the most popular for sharpening pocket knives (or knives). But, before  you go into the sharpening, you must prepare the whetstone beforehand.  Don't worry, it's quite easy. The majority used can be done by dipping the stone in water for about 15 minutes. Regardless of what type of whetstone you use, never use it while it's dry. It's important for a clean sharpening. Using mineral oil is another way to prepare a whetstone. It'll absorb into it once you begin putting the right amount on the surface. How you will determine how much to put is to ensure a "thick film" is lathered across the entire surface. This is critical when you learn how to sharpen a pocket knife.
Whetstones may be natural or artificial stones. Artificial stones usually come in the form of a bonded abrasive composed of a ceramic such as silicon carbide (carborundum) or of aluminium oxide (corundum). Bonded abrasives provide a faster cutting action than natural stones. They are commonly available as a double-sided block with a coarse grit on one side and a fine grit on the other enabling one stone to satisfy the basic requirements of sharpening. Some shapes are designed for specific purposes such as sharpening scythes, drills or serrations.[9]
Hold your knife at approximately 20° in relation to the honing rod. Your angle doesn't need to be exact, just approximate. Whatever angle you decide to choose, or unwittingly end up choosing, make sure to maintain the same angle throughout the honing process. Changing the angle used during the honing process won't smooth out the metal in the blade as much as using a consistent angle will.[4]

Silicone Carbide whetstones on the other hand, are the fastest cutting of the three types of oil stones and the stones made by Norton are called Crystolon Stones. Also they too are graded as either fine, medium, or coarse stones depending on their grit. But, although these stones will not produce an edge as fine as Arkansas Oil Stones or India Oil Stones, their fast cutting ability makes them ideal for sharpening tools as well as for cutting the initial edge bevel on extremely dull knives or repairing the edge on damaged blades. Last, because they sharpen so quickly, it a common practice to start with a coarse Crystolon Oil Stone and then progress to either a medium or fine India Oil Stone and then to finish with an Arkansas Oil Stone.
The coarse stone will cut the metal off quicker but it is going to give you a rougher edge but that way the job gets done quicker, without the oil. It is not as messy. This is just a real simple set up. If you do wood work you can make a little wooden box and rout it out. In this particular case it is just a 2x4, stone traced out, finishing nails tapped down so they are deeper than the stone so when you drop the stone in, if you are at a workbench you can C-clamp it down in place or you can hold on to it.
Manufacturer contacted and sent a new one for replacement. Great customer service but replacement item was nicked on the corner. It was still usable so i didn't bother to ask for another replacement. I would recommend item to be shipped in another box instead of an over-sized yellow envelop which is not adequate protection. Item sharpen my knife pretty good though..
Diamond sharpening stone delivers fast cutting and sharp edges. They are tougher in material and doesn’t flatten. Therefore, it is the best way on investment if you want such of the sharpener that easy to maintain and practical to use. Diamond sharpening stone doesn’t require water other than a spill. It is also applicable to use with lubrication if you wish to.
I purchased this set together with the 400/1000 grit stone assuming that some of my knives were quite dull and would need work on a coarse grit stone. Premium Whetstone Sharpening Stone 2 Side Grit 400/1000 | Knife Sharpener Waterstone with NonSlip Rubber Base & Flattening Stone. This is my first wetstone. First off I tried to sharpen my Chicago Cutlery boning knife. This knife is nearly thirty years old, has been abused in may ways and was quite dull. It was very difficult for me to get a burr on this blade, which I attribute to poor technique. Next I moved on to my Henckels Professional S paring and chef's knives. The paring knife was moderately sharp and was modestly improved after working over all three grits of stone. It would cut paper but again it was difficult to develop a burr with this blade. Undaunted I switched to the chef's knife. This knife is twenty years old and has never been professionally re-sharpened. I have sharpened it twice with a Lanksey sharpening system which marred the finish but did put a good edge on the blade. Lansky Standard Coarse Sharpening System with Fine Hones. The chef's knife was moderately dull and had several pits visible on the cutting surface. I modified my technique for passing the knife over the stone and worked the chef's knife over the 400 grit stone aggressively and eventually I was able to get a burr to form from the tip of the knife all the way to the handle. From there it was a simple process of reforming the burr on the 1000 grit stone and then finishing on the 6000. After sharpening, the chef's knife easily and cleanly slices a tomato with very light pressure and is in my opinion very sharp. Not sushi knife sharp but more than enough for the chopping and slicing I expect of it. I'm looking forward to going back and working both the boning knife and the paring knife over again. Don't expect a good result from this product the first time you use it. Watch videos on using a wetstone, expect to spend at least twenty minutes per knife at first, and practice forming a burr. If you can form a burr, you will be able to successfully sharpen your knife.