These grips are made from the same material used in dirt bike and BMX grips: Kraton Rubber. They are softer and more comfortable but also wear quicker. Just like a dirt bike, plan on changing them often, depending on how hard you ride and in what conditions. Note: Using Biltwell rubber grips on H-Ds will often require that your motorcycle is equipped with an aftermarket throttle tube (our Whiskey throttle tube, for instance). The grips do not have a built in plastic throttle tube, they are meant to slide over a higher-quality aluminum tube.