Using a knife sharpening steel is the only safe way to touch up the edge of your knife without removing material. The steel simply straightens out the edge of the knife without actually taking metal off of the blade apex.
Kitchen knives that were originally sharp can have the apex 'roll' over during regular use on tough food. A steel can straighten the apex back into place making the knife cut well. Western knives using German steel (or similar) are designed to be used in conjunction with a steel. Professional restaurant chefs and butchers use a steel regularly throughout the day to keep their knife edges cutting properly.
This steel has a high tungsten content so will last an extremely long time. Just wipe off with kitchen roll from time to time.
You can use the steel vertically with the tip resting on a soft surface and run the knife along side at a 15 to 20 degree angle. Alternatively you can hold the knife stationary and run the steel alongside. Just bear in mind kitchen knives are ground at an angle. Try to match the knife angle as closely as possibly when you are honing with the steel.
12 Inch long (excluding handle)
In stock here in the UK.