It is unique that Naniwa itself takes care of the production of the binding agent. Chosera is a high-end series from Naniwa made of aluminum oxide with the magnesia binder. With these cookies we and third parties will be able to follow your behaviour on our website. 400 Grit Chosera Water Stone (Green) 600 Grit Chosera Water Stone (Blue) 800 Grit Chsera Water Stone (Peach) 1000 Grit Chosera Water Stone (Green) The Chosera 1000 grit is perhaps the best 1000 grit water stone on the market in terms of performance, feedback and speed. Specifications . With these cookies we and third parties will be able to follow your behaviour on our website. We are offering the full Chosera range, from 400 grit to 10K, along with the Naniwa 320 Pro, 600 Bubble Gum, 1K Chocolate Bar, 1K Goken Pro, and 4K Finisher.