Choose the style of stone. You'll need to choose a natural or synthetic stone that can be used wet (soaked in water), with oil, or dry. There are also diamond stones that are actually very small diamonds attached to a metal surface. Stones that are soaked in water are softer stones which means you can quickly sharpen your knives. Unfortunately, these stones will wear down faster than the others. Oil stones are the least expensive and they're made of a harder material.
Just to prove that we're not merely sharpening geeks, here's an interesting side note. The word whet pops up in some unexpected places. A small species of owl is called the saw-whet owl because the sound it makes reminded people of the sound made when sharpening a saw with a file. And the phrase "to whet your appetite" comes from the idea of your hunger growing sharper at the thought of food.
It looks like it can be a Sci-Fi film prop. This is a 2 stage type of sharpening system. You'll get a non slip cushion with it which is at the bottom offering stability for the user. It's ergonomic handle provides a comfortable and easy grip. This cushion offers the stability needed when sharpening and polishing your pocket knife to it's absolute razor sharpness. The sharpener does the work as you hold down the grip and simply place your pocket knife to get sharpened by the motions of the ceramic and diamond sharpener wheels. Simply run your dull knives through the device and you'll get the results you've been looking for. This one will definitely help you when you learn how to sharpen a pocket knife on the Priority Chef.