The RF remote has a model number RC65RX (above the TV Input button). As was already said, the HR receivers are RF capable, and the H24 is also capable. The H25 requires a separate dongle to make it RF ready. And yes, the HR24s DO come with the RF remote, but it is defaulted to IR mode.
To change the receiver/remote to RF mode, Menu > Parental, Fav's & Setup > System Setup > Remote Control > IR/RF Setup
Switch Remote Type to RF, and click Continue. Follow the onscreen directions for programming the remote to RF.