Use the dressing stone to rejuvenate a worn diamond blade. Cut one or two thin slices off of the stone as shown, and the stone will sharpen your blade, restoring good cutting action. The dressing stone will work on any diamond tools such as saw blades and grinding bits. The152mm  length allows for many, many cuts, and a single stone will last many years.  Use the stone sparingly as some (worn) diamonds will be removed in the rejuvenation process.