Precautions: The knife sharpener is not intended for sharpening serrated knives or ceramic knives, but for fruit knives, kitchen knives, cleavers, scissors, etc. Do not use excessive force or pull back and forth during operation. The Perfect 4-in-1 design: With the 4-stage knife sharpener you can sharpen dull knives easily and professionally. 2 tungsten steel levels for chisel and coarse sharpening, diamond level for fine sharpening, ceramic stone level for precise sharpening. Simple and safe to use: The non-slip rubber mat on the underside provides firm support so it cannot slip. We even have a cut resistant glove for added safety! Simply place the blade in the slot and gently pull the knife in one direction several times for quick and efficient sharpening. Stylish ergonomic design: The ergonomic handle allows easy use by both right and left-handers. The non-slip underside of the handle keeps the sharpener stable and lies comfortably in the hand. Anti-rust plate with anti-rust cushions on the underside provide a more stable base.