Multifunctional 2-Stage Knife Sharpener- This kitchen knife sharpener can quickly sharpen very dull or damaged blades quickly and effectively, and restore dull knives to their original sharpness. Durable Abrasives and Excellent Knife Sharpening Performance- All knife sharpening materials have passed 10,000 field use tests. Strong Suction Cup- Features a strong suction cup base for maximum grip and locks it onto your kitchen countertop with a simple twist mechanism, increasing your safety during sharpening. Suitable for right-handed and left-handed users. Small enough to store anywhere. Applicable Knives- Straight-edged steel kitchen knives and wide serrated knives (bread knives), including those with hardened steel blades. DO NOT USE ON: ceramic knives, scissors or micro serrated knives.