As always; which is very good. Solid brass, durable and easy to pocket or pack. It's strange that so many people spend so much time reviewing, testing, and developing knives, yet so few people think about what makes a knife useful: the ability to cut. If you buy this device, you don't have to think about it either. This is a sharpener that will give you many years of pleasure. My dad still uses the one I remember using when I was 8. It's 30 years old and I believe. The only caveat I have is for the first or second time you use it. Sharpen a knife that you don't particularly need. When the coating or compound on the racquet is new, it becomes very "sticky" and uneven, like sandpaper. It works quite quickly and lasts for a very, very long time. Just wash with soap and water from time to time.