If you need a sharpener very effective and inexpensive that you can carry around in your bag this stuff is great, on a not too sharp knife is obtained a cutting almost razor qq minutes. But be careful what type of mini sharpener is only useful to maintain a correct blade wire by using it regularly, if the wire is a remake, it must turn to a more substantial kind kit "Lansky deluxe set" or even better : The "Sharpmaker" Spyderco. We must also regularly maintain the 2 bars ceramics by washing with hot water and washing up liquid when they became too dark (metal powder deposit) because at this stage it greatly lose their abrasive power, soap blow and go again! After 2 years of frequent use I am still happy.
