A flattening stone? Naniwa does mame them but it would be much better if you got a diamond plate of so.e kind enstead. A diamond plate will always be flat. Works well for raising slurry and flattening your stones. Along with correcting things on your razor. A flattening stone can not do but one thing and im not sure how flat it will be to start with. BTW, Ive never used a flattening stone. So take this with a grain of salt. But Im sure many here will agree with me.