I’ve been very impressed with the Ninja Foodi NeverDull Sharpener. It’s the first knife sharpener I’ve used that actually works. It’s an incredibly simple process – just insert the knife, slide the lever up and down 10 times, and press the release button for a perfectly sharpened blade every time. The stone sharpening wheel moves up and down with the lever, engaging the full length of the blade with each stroke. The edge of the knife comes out as if it were brand new. There’s no movement or wobbling of the knife once it’s engaged in the sharpener, which means that the angle of the sharpening wheel is always perfectly aligned with just the right amount of pressure. Excellent!