If you purchase a Shavette Black you get Dovo Solingen shavette and also black and red blade holders for the razor blades. The red blade holder is suitable for all normal double edge blades. If you are using long shaving blades you can store them in the supplied black blade holder.
Advantages with a shavette compared to a straight razor is that you don't have to sharpen your shavette. You simply change the razor blade when it starts to feel dull. Here is some information about the basics of how to shave with a shavette.