The Zwilling TwinSharp Knife Sharpener is perfect for all knife lovers to keep that WOW factor when cutting into a tomato.
It has a coarse wheel to bring the edge back and then a fine wheel to polish it and keep the edge sharp for longer.
You simply glide the knife backwards and forwards on the coarse wheel around 5-15 times (all depends how blunt the knife is, it may need more). Cut into an onion or tomato to test it's sharpness.
When you've got the edge back then glide the knife through the fine wheel just a few times to polish and get rid of any burr.