Naniwa Super Stone 800 Grit Japanese Whetstone Sharpening Stone, NO Stand, 21cm x 7cm surface, 2cm thick.
This medium-fine stone is perfect for grinding a new edge on your knife, or for doing regular touch-up work when you don't need to remove much metal and so don't need to use a very coarse stone to start with.
The Naniwa Super Stones are excellent whetstones, very reliable, forgiving, and not fragile. A GREAT choice for the beginner or casual home user who just wants good long-lasting stones that work great on a variety of knives. I use these SuperStone series at home and they're great. They're also easy to use: just splash-and-go, no need for soaking and in fact they should NOT be soaked.
Warranty: One-year warranty against manufacturing defects.