When the block is intended for installation on a bench it is called a bench stone. Small, portable stones (commonly made of bonded abrasive) are called pocket stones. Being smaller, they are more portable than bench stones but present difficulty in maintaining a consistent angle and pressure when drawing the stone along larger blades. However, they still can form a good edge. Frequently, fine grained pocket stones are used for honing, especially "in the field". Despite being a homophone with wet in most dialects of modern English, whetstones do not need to be lubricated with oil or water, although it is very common to do so. Lubrication aids the cutting action and carries swarf away.
The price of a whetstone is most often indicative of its quality, which directly correlates to how hard the stone is. “The more expensive stone, typically, is comprised of a harder material, which is efficient at grinding metal off of a good-quality knife,” Lau says. “It allows you to sharpen quicker [and] it allows you to sharpen a very high-quality knife, whereas a cheaper stone may not create a good edge if a knife is made from a very hard metal.” A well-made whetstone should cost $60 to $70.
Prep your stone: To adequately lubricate the stone, rough and medium whetstones should be soaked in water for 20 to 30 minutes, or until air bubbles stop rising, before use. Finishing stones should not be soaked, as they are prone to cracking. Instead, sluice a fine-grit stone with water and use a nagura, or dressing stone, to create a slurry of silt for improved polishing. Once ready, place a sharpening base on a flat surface and fit the whetstone on top of it.
Double-sided stones, with a medium grit on one side and finishing stone on the other, are popular among beginner sharpeners and convenient for home use. Lau recommends the Mizuyama two-sided whetstone ($73), with 1,000- and 6,000-grit sides, for beginners. “The stone itself is very high quality, really geared toward high-quality knives, so you can pretty much sharpen any metal with this one.”
I recommend keeping two stones in your kit. One with a medium grit (around 800 or so) to perform major sharpening jobs, and one with a fine grit (at least 2,000) to tune the edge to a razor-sharp finish. For real pros, a stone with an ultra-fine grit (8,000 and above) will leave a mirror-like finish on your blade, but most cooks won't notice the difference in terms of cutting ability.
You've acquired a good chef's knife, you're using it almost daily to make tasty dinners for the family, and it's stored in a nice knife rack or a magnet for safekeeping. So why stop there? Keeping that knife's edge fine will make cooking not only safer but, let's face it, much more fun. Whether you've spent £150 on a high-end knife or under a tenner on a dinky paring knife, keeping it sharp is crucial. 
The fit and finish on this product is amazing. He stone is beautiful and clearly high quality and very well cut. It’s different features on even such a small stone are huge. The leather cord and it’s unique knot is incredible. This is absolutely part of my edc, something I am happy to wear all the time. It’s useful and looks great too. Couldn’t be more happy with it.
Our Whetstone Knife Sharpener Kit Comes With The Following: Double-sided premium quality 1000/6000 fine and super fine honing stone that sharpens and polishes A knife angle guide that keeps blades steady and at a perfect angle for sharpening A cleaning or laaping stone for the sharpening stone that keeps it in tip-top shape An aerated, non-slip, super slick, durable plastic protective box with breathing holes to keep product safe and dry A detailed instruction manual eBook with lots of tips and tricks suitable for every skill level
I'm using this for a set of kitchen knives. As far as their quality goes, they are a name brand, but middle tier at best. The kind you can pick up at a mall kitchen store. They were all dull and in need of sharpening. After using these stones, my knives were all insanely sharp. They were noticably sharper than when I first bought them. I'm not experienced with sharpening stones, so I can't say how these compare with others, but for my needs as a non-professional, this set is perfect. Outperforms my needs.
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 http://video.about.com/culinaryarts/Sharpen-Knives-With-a-Whetston.htm?rd=1 http://culinaryarts.about.com/od/knivescutlery/ht/whetstone.htm this is a video that says don't use water http://video.about.com/culinaryarts/Sharpen-Knives-With-a-Whetston.htm?rd=1 this is a youtube video that i watched that uses water. *informative http://www.youtube.com/watch?v=KFIg9Cm-nJg