As all cyclists are too aware, materials such as dust and dirt picked up during a ride - as well as moisture - can play havoc with the condition of your bike and its various components.
When it comes to the handlebars, the single most important contact point providing the stability you need to not just point the bike in the direction you want to go, but also in holding on, it's vitally important to maintain the strength of the bars as well as keeping it looking great on the outside. One of the main threats to the structural integrity is moisture and the resulting rust that can build up as the damp gets into the end of your bars.
To counter this, handlebar end plugs have been designed to slot simply into the ends to stop the bars filling with dirt and any moisture, too. Bar end plugs can be slotted or screwed into the handlebars, depending on the style you choose, and can make a massive difference in the lifespan and structural integrity of your handlebars, so if you've experienced rust or continually see dust and dirt all over your bars, give a set of bar end plugs a try.