Eze-Lap diamond plates have been manufactured in the US since the 1970s and use a unique process and modern technology to produce the highest quality diamond plates. The continuous diamond plates cut the fastest and most efficiently, with the best edge produced of any diamond plate worldwide. The high-quality industrial-grade diamonds are bonded on to a 1/4in thick steel plate substrate to ensure perfect flatness and long-life durability. Once coated the plates are approximately 6.5mm thick. Unlike cheap Asian diamond plates, as the diamond surface wears down, more and more diamonds are exposed and the sharpener cuts faster. With more pressure applied, the plate will cut even faster. With care, these sharpeners can last a lifetime.