These are simple in design and the anodized end caps look great on my bike, and you can use them for either road or mtn bars, but I used them on my old school mtb. The plugs work by using an expanding plastic shroud that has a metal bolt through the center. You tighten the bolt, the plastic shroud gets pulled into the conical end of the plug and makes the plastic expand, putting pressure on the inner wall of your handlebar so it keeps the plug in place. I like these better than the plastic plugs that you have to hammer in place because you can reuse these, if you want to change colors you just unscrew the bolt until the plastic loosens and the plugs slide right out. You can buy them in most colors to suit your taste and they aren’t very expensive. So if you are looking for a set of plugs for your bike and you don’t like the cheap plastic stuff that usually comes with bar tape or grips then try these. I give them 5 stars.