The addition grindstone "Spyderco knife sharpener Ultrafine Stone" expands the Set "Spyderco Knife Sharpener Tri-Angle Sharpmaker" and brings the - important for me - little bit of sharpness.
Attention: for a practical handling 2 pieces are necessary !!!!
I'd love to give it 5 stars but for the price (€ 44, - for 2 pieces) is too high.