DMT® Diamond Sharpeners are an excellent value because of their durable construction, quality and reputation for providing years of uncompromising service. Unlike conventional oilstones, Japanese waterstones, Arkansas stones and other ceramic sharpeners, DMT® Diamond Whetstones ^TM will not break, chip, crack, hollow or groove. Do not be fooled by other diamond sharpeners made in other countries who claim their products are just as good - If you want the best care for your edge, demand DMT®!