This is one of the most popular knife sharpeners in the market.It is with Vacuum sucker design,safe and convenient.The Knife sharpener is extremely simple to use. First, attach the vacuum suction cup foot on a smooth and stable surface. You now have both hands free and can run your knife along the grinding wheels. The suction cup with its vacuum system provides optimal stability on all smooth surfaces. The two wheels - one for coarse and one for fine grinding - are coated with diamond powder. First you draw them through the coarse side and then through the fine side. The grinding angle is fixed - so it can't go wrong. It's that simple. Use the sharpener to sharp your knife in an easy and convenient way and enjoy your kitchen life.