All Naniwa Professional stones are splash and go. A binding agent unique to Naniwa bonds the material and makes for a more consistent grit size and therefore a more consistent sharpen. Naniwa Profesional perform best with low alloy steels (ie. shirogami and aogami)

Naniwa Professional 400 - The coarse material is very effective at cutting through material efficiently and consistently yet should last a while. 

Naniwa Professional 800 - The 800 stone is perfect for quick results when putting a fresh edge on a knife. One of the best on the market.

Naniwa Professional 3000 - A very high quality finishing stone with the ability to get the knife razor sharp.

Also, take a look at the more inexpensive Naniwa Super range.