Strange, these aren't real like you find at other suppliers, but usually at a higher price. I rebuilt some real 9mm covers on my bike's valve stems and put them on my cruiser bike for fun. The upside is that if they fall off or get stolen, it's okay. You look neat. In addition, they are lined with plastic, which is a big plus, since a metal-lined product can rust on the valve stem. No Bueno.