Diamond dresser SD-80
Synthetic diamond rod will provide constant sharpness.
Keep the grinding wheel sharp and correct
As you sharpen, the grinding wheel needs to be dressed every now and then to make new grit available or to reshape it. A poor finish underneath the skate blade or blade chatter (even though you have dressed the grinding wheel) is probably a sign that the diamond is dull and needs to be replaced.
With average usage, a diamond dresser is sufficient for 4 grinding wheels.