Combination diamond whetstone
If you're happy hand sharpening without any guides, then this kit is ideal. I've had it for 2 years now and sharpened hundreds of knives including supersteels and it's handled them all with ease. With really poor damaged edges, I've done some base setting on a grinder, but for most blades a few licks on the stones gets them shaving sharp. For hair whittling sharp, I then go to micromesh on a strop