Atoma is a quality diamond sharpening plate from Japan. The manufacturer is Tsuboma. These plates or as I call them stones are almost same size (75mm x 210mm) as a typical whetstone. The size and quality give these stones a long lifetime. The only thing you have to remember is that it is strongly recommended to use water. Never use diamond stone dry.
Another thing to remember is not to use too much pressure while sharpening. While this on mind you will have longlasting sharpening tools on your hands What separates Atoma from other diamond plate manufacturers is the production technic. Diamonds are placed to the surface of the plate on straight rows & columns. Take a look at the microscope picture behind each grit. This laying method means that there is not going to be large holes or areas where small items might get stuck while sharpening. With Atoma you can also use edges of the plate more securely compares most of the other competitors
We currently hold 4 grit levels on the stock. 140 and 400 are very good lapping stones and good for any rough sharpening. 600 works as a medium-fine stone and 1200, on the other hand, is an excellent fine stone. It can be compared to a typical 1000 grit stone.
Atoma diamond plate is clued to the surface of the aluminum plate. You can also buy a replacement sheet separately. This allows you to create a stone where you have 400 on the other side and 140 on the other side.