These waterstones are a game-changer! Thanks to my knowledge gained in practice I can confidently say that these stones are beyond compare. They produce a razor-sharp edge with minimal effort, making them an ideal choice for professionals and DIY enthusiasts alike .The purple grit is perfect for final honing and polishing. Industrial and Scientific-grade quality ensures the longevity of the stones. The only drawback is the high cost, but the RESULTS they deliver are well worth the investment..