A coarse #400 whetstone from Naniwa's Super Stone "Splash and Go" line — no soaking required, just splash on water and sharpen. Naniwa has produced abrasives and sharpening stones in Japan for over 60 years. This grit is the starting stage for repairing chips and resetting a truly dull edge before moving to finer stones.

• Grit: #400 (coarse)
• Type: Splash-and-go waterstone — no soaking needed
• Model: S2-404, Super Stone series
• Brand: Naniwa, Japan