Chinese 12000 grit or C12k for short. For just a quick refresh of the edge it will do the job. There are better choices out there, but for the budget concious you won't go too far wrong. A 4k/8k combo would be my next purchase after that. Don't forget to lap the stones flat before you use them. That would do you for a good while I'd think. Unless you acquire the dreaded HAD...:)
Mick